I think a config option to exclude armor trims from additional loot would be good too. Reason being that armor trims are quite deliberately placed in specific chest loot. For example, the snout armor trim should only be in bastion chests and silence only in ancient cities, etc. I would personally like to maintain that thematic tie between armor trims and specific chests/structures.

Added an "ignored" item tag in version 4.3:
https://github.com/someaddons/LootIntegrations/blob/1.20.1/src/main/resources/data/lootintegrations/tags/items/ignored.json
Add items to it via datapack that should not appear in any loottable. Note that in 1.21 the folder name is just "item" not "items"