NEW UPDATE: Pistol Dancer should now work as intended and grant the perks it says it does. There was an issue with the Psi-Bow where the Reload ability just wouldn't show up. This should now be fixed as well.

Thanks for your feedback!
I updated the mod with an added Ability Restriction for PM_Shot and PM_Shot_All for Primary Pistols.
Otherwise I could also try and see what happens if PM_Shot_All simply doesn't override PistolStandardShot, but hopefully the Ability Restriction is enough to fix the issue.

hello, Matt! There is a consistant issue regarding the Puella Magi class.
Both on my and Tech's setups, when we pick up Pistol Dancer, the class itself gets UNABLE to attack, the icon disappears completely.
Not only that, Pistol dancer does NOT give Serial, and if you dual wield, which gives the ability to shoot back, it doesn't activate momentum either.

I did extended tests, and I can confirm that this issue resides entirely within Puella Magi's Pistol dancer. I did some digging in the code, and I only theorized that PM_Shot_All, which overrides PistolStandardShot, therefore removing the ability to shoot, is not itself available for the Primary Pistol. But I may be wrong.

I managed to work around it using Iridar's Loadout Manager. I just needed another grenade launcher primary soldier to save the primary weapon I wanted, then loaded it into the Magi and that worked. I just need to not touch it now. Not ideal but it's better than having to tag as incompatible and never use it. It probably is another mod of mine causing shenanigans (I do use over 900 after all), but at least I can still equip it this way. Thanks for checking, mate!

I made an AbilityRestriction for the Launch Grenade skill to allow FragCannons to launch grenades like normal. No idea if that is even related to the issue, but I guess it's nice to have either way.
I then started testing the issue you described with Ascetic Magi + Support, but with my mod setup the class could equip the FragCannon normally. Using Primary Secondaries or True Primary Secondaries also made no difference.
So I'm guessing that the issue is fixed or that there's something else in your mod setup that causes the issue. Note that FragCannons are weapons that have to be built in Engineering. I set the mod up to equip new Ascetic Magi with one anyway, basically giving it them for free. But if you're using mods that change how Engineering / building weapons work or what soldiers equip on promotion, this could be what's causing the issue.

I had a similar issue with the SuperSoldiers mod before where primary weapons couldn't use certain skills from secondary specs because the game expected that weapon to be in the secondary slot.
Not sure if that is related since you said the weapon cannot be equipped at all, but I could try to fix the issue with Ability Restrictions or Ability to Slot Reassignment to allow the FragCannon to use grenade launcher skills.
I'll try some stuff out when I have the time.

Unfortunately been running into major issues with the Ascetic Magi on stream and did some digging. Any secondary grenade launcher spec (Grenadier/Demolitioner/Support) seems to completely break the class' weapon loadout, seems having a primary grenade launcher and secondary grenade launcher from the Primary and Secondary specs are cancelling each other out and you cannot equip a grenade launcher/fragcannon at all.

I've had to tag them as incompatible, which cut the amount of total classes from it in half. Not sure if it's fixable, as I've asked on the modding discord, doesn't seem to be an easy fix

IMPORTANT NOTE:
If you used an older version of this mod, updating it will BREAK all soldiers using any of the Magi specs! Please see the changelog to find out how to fix this.