To my knowledge define modules setup prior to this update will still work as normal, however as always it's best to test missions after updates.

-Added delete groups/vehicles parameter to define modules, which is enabled by default.
If you want to use the groups or vehicles you're defining for something else then you can now tell the RGS modules to not delete them.

-Define modules can add groups/vehicles to multiple pools
Can add synced units or vehicles to multiple pools by entering multiple pool names with comma separation

-Added unit/vehicle init parameters to define modules
If there's a piece of code you want executed on every unit or vehicle in a pool you no longer have to put that code in each individual spawn module.

-Waypoint Builder wave formatting
When using the waypoint builder it will now detect if you have waypoints from multiple groups selected, and will automatically put it into a format accepted by the wave modules. Note that this formatting would not work in the normal spawn modules.

Documentation has been updated to reflect changes.
https://docs.google.com/document/d/1v2JQEiU6dfEuDSPdFnXBkXpoKG7Rg8mS9tDVf8blLeg/edit?usp=sharing

-Speculative fix for issue where AI are hurt/killed when teleporting to garrison positions.
This is only for the Garrison and Spawn Garrison modules, it doesn't affect Spawn LAMBS Garrison.
I say speculative as I can't confirm it fixes the issue in all circumstances, however in situations I saw during testing the success rate was 100%.

As a slightly more technical explanation:
The fix was essentially setting the velocity of units to 0 before they teleport, as I believe they were maintaining velocity from their initial movement prior to being teleported and clipping into objects, hurting/killing them.
Obviously if a garrison position is in a stupid place they'll likely still be hurt/killed.

-Fixed issue where units being placed into positions by the Group Garrison or Spawn Group Garrison modules weren't being put in the right place if said position was over water.

Hotfix
-Fixed issue where Define Vehicles modules didn't have the Gear Randomisation parameter workaround applied, causing errors if those modules had been placed in previous versions, but not opened in 3den since the last update.

Quite a lot has been added or tweaked in this update, so there may be some teething issues. Please refer to the documentation if anything isn't making sense.
As usual I refer to the disclaimer:
DISCLAIMER: Updates may change the functionality of existing modules within the mod, meaning existing configurations in created missions may be invalid and must be reconfigured.
Whilst I will try to avoid this, I will do it if it’s for additional features to improve the mod. It is YOUR responsibility to ensure YOUR missions using this mod still work after updates.

If you find a bug that I've missed please tell me and I'll endeavour to fix it when I can.

Update log is too big to fit in here, so here's a link to a Google Doc
https://docs.google.com/document/d/1OTj35lXAo5e6_SWkj28bmDfpmQ7bizO7uwg33h1_bWE/edit?usp=sharing

Hotfix
-Fixed issue where the spawn vehicle functions were looking for the wrong variable name for the unit init field.

Major update soon hopefully(tm)

Reverted to 3.01
-I think something used by the update to ensure the vehicle group leader is correct is causing some CTD issues that weren't occurring during testing.

Will try alternative methods.

v3.1
- The group leader for custom vehicle crew will now be correct. Before the group leader was always the driver, which didn't work well with certain vehicles that doesn't allow the driver to both command and drive for some reason, so they just refused to follow waypoints.

Just dragging the group into the vehicle will still work with most vehicles as the driver can be the group leader, however some notable exceptions to this include RHS BTR's, that need the group leader to be in the commander seat to actually have it follow waypoints.

Knowing Arma this issue will still continue to plague me no matter what I try, so be aware that some vehicles may still have issues.

v3.01
-Fixed some tooltip errors.

v3.0
Existing missions with RGS modules will need to have their configurations checked. There've been a wide range of changes that break original setups. I released it on Monday so there's more time to fix missions before peak hours on weekends. I also refer you back to the disclaimer on the mod page:

DISCLAIMER: Updates may change the functionality of existing modules within the mod, meaning existing configurations in created missions may be invalid and must be reconfigured. Whilst I will try to avoid this, I will do it if it’s for additional features to improve the mod. It is YOUR responsibility to ensure YOUR missions using this mod still work after updates.

Mod now requires CBA and Zeus Enhanced, LAMBS is still optional.

I recommend consulting the updated documentation[docs.google.com].

Added:
-Spawn Scheduler
The scheduler will take the information from spawn modules, and spawn groups one by one. This is to improve overall performance when spawning a large number of groups in a small amount of time. Can be enabled and configured through your addon options.

-Zeus Modules
Can define and spawn groups/vehicles.

-Separate LAMBS Spawning Modules
Rather than being split between Attack, Defence, Patrol, and Search, the LAMBS spawning modules are split by individual waypoints, allowing for all waypoint options to be available without over-cluttering the modules.

-Conditional Wave Spawner
Module will spawn groups infinitely until the condition parameter is false.

Improvements:
-File Structure
Mod is now setup using the CBA structure.

-Functions
Functions are now cached with CBA PREP, which supposedly drastically speeds up load times compared to having functions defined normally.

-Group/Vehicle Pools
Custom group/vehicle pools can be defined and spawned, allowing for a theoretically infinite number of different group/vehicle types.

-More defined parameters
Define modules now store more information, such as unit face and rank.

-Tooltips
Tooltips for the majority of module fields have been improved to explain functionality better.

-Spawn Group Waypoints
Spawn Group, Vehicle and Wave modules now support a theoretically infinite number of waypoints.

-Inits
Can have code execute on each spawned unit/vehicle if needed.

-Module Areas
Most LAMBS group modules make use of the module area functionality, allowing you to more precisely define an area for LAMBS waypoints.

-Numerous code optimisations

Probably a bunch of other stuff I forgot about.