What's the use case for Pact Equipment Boxes?

[Paramatter.4628]

I saw that there was a recipe for these invisible equipment bags and I just can't really understand what would really make them preferable to ordinary invisible bags. I considered maybe if you were carrying alternate equipment around it might get sorted in when you swap things out but it didn't seem to work that way with visible equipment boxes, but maybe I was just testing it wrong. Regardless, just curious  if anyone can explain them.

[Inculpatus cedo.9234]

The difference:

Invisible Bags/Invisible Packs/Safe Boxes/Courier's Bags — Items in these bags cannot be sold to merchants nor at the Black Lion Trading Company. Their contents do not move when inventory is sorted. Using 'Deposit Collectibles' will not affect items inside invisible bags; however, items can still be deposited individually using the right-click menu. Using "Salvage All" option on salvage kits won't salvage items put in this bag. (Useful for saving Unidentified gear for later use)

 

Equipment Pact Boxes/Marshal's Bags — Combines the properties of equipment boxes and invisible bags. Unlike other inventory bags, the 20-slot versions are soulbound on acquisition so they can only be used or upgraded by the character that crafted them.

[Paramatter.4628]

That doesn't tell me anything about why combining those properties would be desirable, though.