Don't know when this issue will be fixed but since we discovered the mod doesn't export (Supposedly) C# Genes (B&S Metamorphosis/DET sizes). Turns out manually adding them to the exported .xml will let the mod import the xenotype ingame with genes we want!

Step 1: Do the following to make your life easier and get

For finding GeneDefs, https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=3521312241

For easy xenotype editor access without loading world (or similar mod), https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2891975564

Also export your bespoke xenotype WITHOUT the offending genes (it will say the file exported on top left if successful)

Step 2: We have to find the GeneDef(The internal name for the gene) by using Cherry Picker.
Open the mod option of Cherry picker and use the search bar and type in the name of offending genes.
In this case we will look for the "Morph Teen" (DO NOT USE QUOTATION IN SEARCH BAR DINGUS) gene from "Big and Small - Genes & More" mod. Doing so we will see
GeneDef:: Big and Small - Genes & More(Or your target's mod name) :: BS_Metamorph_TimeTeenage(or your target's genedef). IF YOUR GeneDef looks like this: GeneDef::(THERES NOTHING IN THE MIDDLE) ::VRE_Boarskin_Metamorphosis
don't worry skip Step 3 and we will just do a slight modification at the final step.

Step 3: We now have to find the package id of your Gene's source Mod by using the in-game mod manager. Using our previous example of Big and Small - Genes & More, we will find in the in-game mod manager and select mod causing the mod info to appear on the right side of window. There we will find the package ID, in this case it is "redmattis.bigsmall.core"

Step 4: Putting it all together: Now that we know the our Morph Teen Gene's GeneDef (BS_Metamorph_TimeTeenage) and it's source mod's package ID (redmattis.bigsmall.core) we can now add the genes to our Bespoke xenotype by text editing the .xml file (Basically any text editor works even notepad) Navigate the .xml (going in game into the xenotype exporter menu and clicking the option is the easiest) and keep the xenotype editor in-game open with your Xenotype loaded. Add the offending genes back onto your xenotype with in-game editor. NOTE the location of the Selected GENE relative to the other SELECTED GENES. The genes on the .xml file are placed into a descending list based on in-game Xenotype gene list as if it was reading LEFT TO RIGHT like a BOOK (at least for the Anglosphere) just look and compare its not that hard to put two and two together.

Now we will slot in a new line for the "BS_Metamorph_TimeTeenage" GeneDef from "redmattis.bigsmall.core" package the in the right order inside the xml. It will look similar to this:

<li MayRequire="redmattis.bigsmall.core">BS_Metamorph_TimeTeenage</li>

Now we will add the GeneDef::(THERES NOTHING IN THE MIDDLE) ::VRE_Boarskin_Metamorphosis gene to the .xml (Still must be in order of appearance) since it has no MOD NAME we don't need one and it will now be a new line that look this: <li>VRE_Boarskin_Metamorphosis</li>

Now this lists looked from this:

<genes>
<li>Pain_Reduced</li>
<li>Immunity_Strong</li>
<li>StrongStomach</li>
<li>RobustDigestion</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_Gluttonous</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_RapidAging</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_CurledTail</li>
<li>Ears_Pig</li>
<li>VoicePig</li>
<li>Body_Standard</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_AuburnSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_ChocolateSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_HazelnutSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_PigSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_PorkFlesh</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_Coward</li>
<li>Hands_Pig</li>
<li>Nose_Pig</li>
<li>AptitudeStrong_Melee</li>
<li>AptitudePoor_Cooking</li>
</genes>
</XenotypeDef>
</Defs>

To this:

<genes>
<li>Pain_Reduced</li>
<li>Immunity_Strong</li>
<li>StrongStomach</li>
<li>RobustDigestion</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_Gluttonous</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_RapidAging</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_CurledTail</li>
<li>Ears_Pig</li>
<li>VoicePig</li>
<li>Body_Standard</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_AuburnSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_ChocolateSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_HazelnutSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_PigSkin</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_PorkFlesh</li>
<li MayRequire="vanillaracesexpanded.pigskin">VRE_Coward</li>
<li>Hands_Pig</li>
<li>Nose_Pig</li>
<li>AptitudeStrong_Melee</li>
<li>AptitudePoor_Cooking</li>
<li MayRequire="redmattis.bigsmall.core">BS_Metamorph_TimeTeenage</li>
<li>VRE_Boarskin_Metamorphosis</li>
</genes>
</XenotypeDef>
</Defs>

Hopefully this is not too confusing to do and enjoy you guys' crazy baseliner but is a secret sanguophage angel demon snake cthulhu hybrid