As of dmg not applied:
I tested locally and found the source of frustration.
I used +4 1d4 piercing/bludgeoning/slashing gloves (so each are +4 and 1d4 of single dmg type) to make sure things are exactly how they are with your example.
In my test, gorgon has such damage modifiers:
2d8 dmg slashing as base creature damage
+8 from str
in other words, it's 10-24 dmg.
Gloves themselves should add:
+4 base dmg type
+1d4 of selected dmg type.
So, if no 1d4 is not of same type as base weapon dmg, then dmg should be 15-32.
In any case, the only real proof that it applies is if gorgon deals over 28 dmg without crit. Since it's 10-24 base and +4 EB makes it 14-28. So, if i get any hit with dmg of 14, it's automatic "doesn't apply" and if i get any hit with 29-32, it's automatic "does apply".
Gorgon (base slashing dmg):
Ref pic:
1) Bludgeoning gloves:
Expected dmg: 2d8 + 8 + 4 + 1d4 = 15-32, 14-28 without 1d4.
126 hits, none of them went below 16 dmg,1 hit dealt 32 dmg (not crit), so it applies.
2) Piercing gloves:
Expected dmg: 2d8 + 8 + 4 + 1d4 = 15-32, 14-28 without 1d4.
78 hits, minimum dmg dealt 17, maximum dmg dealt 30, so it applies.
3) Slashing gloves:
Expected dmg: 2d8 + 8 + 4 + 1d4 = 14-28, because it's slashing shape so 1d4 shouldn't apply.
173 hits, minimum dmg dealth 15 (5 times), maximum dmg dealt 28 (5 times), so it definitely doesn't apply. No regular hit damaged over 28 dmg.
Werewolf (base slashing + piercing dmg, physical in other words):
Ref pic:
NB, i turned off werewolves lacerate ability so it doesn't mess into my testing data. It only applies to my local testing setup, doesn't affect live server in any way.
1) Bludgeoning gloves:
Expected dmg: 2d6 + 6 + 4 + 1d4 = 13-26, 12-22 without 1d4.
2 hits, maximum damage dealt 23 without crits.
So few hits because second hit did already show that bludgeoning applies.
2) Piercing gloves:
Expected dmg: 2d6 + 6 + 4 + 1d4 = 13-26, 12-22 without 1d4.
57 hits, minimum damage ealt 13, maximum damage dealt 23 without crits.
So, piercing 1d4 gets applied.
3) Slashing gloves:
Expected dmg: 2d6 + 6 + 4 + 1d4 = 13-26, 12-22 without 1d4.
201 hits, minimum damage dealt 12, maximum damage dealt 22 without crits.
So, slashing 1d4 definitely doesn't get applied.
Summary:
There are such creature weapons type by damage:
Bludgeoning (so 1d4 bludgeoning won't stack with it if has EB bigger than 2 from any source)
Piercing (so 1d4 piercing won't stack with it if has EB bigger than 2 from any source)
Slashing (so 1d4slashing won't stack with it if has EB bigger than 2 from any source)
Slashing + piercing (so 1d4 slashing won't stack with it if has EB bigger than 2 from any source. but 1d4 piercing
will stack with it).
Shifter shapes weapon stats. Creature has single weapon unless i specify other:
1) Dryad: piercing (bow)
2) Werewolf : slashing + piercing
3) Gelly cube: bludgeoning
4) Owlbear: weapon 1: slashing, weapon 2: slashing + piercing, weapon 3: slashing + piercing.
5) Manticore: weapon 1: slashing, weapon 2: slashing
6) Pixie: piercing (bow)
7) Wyvern: weapon 1: slashing, weapon 2: slashing, weapon 3: piercing
8) Gorgon: slashing
9) Ogre magic: bludgeoning (warmace)
10) Mindflayer: slashing.
I hope this information will help you getting it clear what glove properties will/will not work for which shape.
Thanks for pointing out at this situation. It's not something we can fix, but it's something we can get people informed of.