The soulbound maker would allow a player to mark a number of items as soulbound, for example you could make a sword and all your armor or all your modded equipment, unlike a soulbound enchantment, it is easily changeable but you cannot make more. This could be used as a sort of loadout system

The mod supports a soulbound item tag. You can read about it here.
You can also configure specific slots to have specific drop rules. For example, inventoryConfig.soulboundSlots can let you decide which slots of your inventory will apply the soulbound trait to the items in those slots.
On the wiki you can read under "Inventory slot IDs" dropdown (right under the config block) which ID represents which slot.

I'm not quite sure if you would want something more specific? I've been thinking recently if there's a way to let each player mark up to X items/slots as soulbound through the inventory individually, that they can change, if that's sort of what you want?
I feel like I would need more details of exactly what you mean, although I'm not sure if my interpretation/thought is detailed enough either to be understood properly either.