There are 16 chars that I was able to give meteor dust to get 4 heart status.
Contains spoilers!

Place: Gear village
Sells blueprints.
Reward:4 heart reward is a portable crafting bench (very useful):


Place: Gear village
Upgrades your arsenal.
Reward:Gives you a disscount and a scavenger chip

Place: Gear village
Mission briefing?.
Reward:Gives you doctor's weapon.


Place: Gear village
Sells chips.
Reward:You can assign your chips anywhere.



Place: Gear village
Sells weapons.
Reward:Gives you elemental blade.


Place: Gear village
Sells junk.
Reward:Better health chip.


Place: Gear village
Takes care of animal shelter. Gives you 1500 for every pet found.
Reward:
Companion dmg chip. It works with cats too.



Place: Gear village
Parry training.
Reward:Parry dmg chip

Place: Gear village
Sells cogs.
Reward:Discounted cogs, cog durability chip:

Place: Multiple places, Industries Outpust next to the teleporter
Sells junk, disposable syringes, pet food and cogs.
Reward:Discount, and also

Place: Next to the fishing spots.
Gives you a fishing rod, sells junk.
Reward:Better fishing rod

Place: Highways South
Duplicates chips (only selected chips, up to 5 times) for 1000.
Reward:Glitch chip (reverses your controls, gives you crit chance in your attacks, and ailment chance like burn, freeze and def reduction). Reversed controls are negated while using 2 or 4 chips. 100% crit chance if you use 4 glich chips.

Place: Downtown outskirts
Sells disposable syringes (600) and it's blueprint (1500), permanent syringes (max 3, cost 3 dust each).
You need to get to her shop first through the roof to unlock main entrace:
Reward:Passive syringe refill chip:

Place: Highway hideouts
Sells blueprints.
Reward:Gives you possibility to upgrade your weapons by yourself. Not sure if gives you also a discount.


Place: Industries Outpust, Gear village
Gives a quest while at Industries, sells dust while at village.
Get her stuff from there:
Return to her place, she will leave you a chest and moves to Gear village:
Afterwards, you will be able to buy dust from her (price increases after each purchase)
Reward:Dust chip - 48 hours instead of 24 works on your char only

Place: Cathedral roof at Cathedral entrance
Gives you time in exchange for somebody elses, specific choice has to be made to unlock true ending.
She is the first step in order to get a true ending, you have to chose her twice as a person for a time exchange. You will have to defeat her to obtain a key card and 10 dust. She was 4 hearts after time reset in my case

Place: Deep woods, Industries Outpust
Go to the following location to trigger the even in which Gabi leaves Joana.
Give Gabi hookshot blueprint to move their quest further (at Industries Outpust).
Speak with Joana again (their locations should be marked as ???).
You will get their hearts full after time reset.
Reward: Cutscene during credits