Am I allowed to have customers bump my sales thread?

I've read several conflicting stickies saying

"customer bumps are allowed every 2 hrs and seller bumps are allowed every 4 hours"

OR

"customer bumps on sales threads must be reported and only the seller may bump every 4 hrs"

and it used to be

"customer vouches may bump your threads at any time" back in 2018"

Now I'm a bit confused and don't want to break any rules.

 

This is in the GFX marketplace and it links to the thread below:
Graphics Marketplace Rules [Updated March 25th, 2021]

Thread linked to from GFX marketplace:
An update to the bump system

I don't know if it's outdated or I'm misunderstanding a per-section set of rules but it confused me a bit.

I'm basically wondering if say I bump my GP/Skilling/Firecape threads and sell to a customer, can they vouch on my thread to bump it up again? If so am I also allowed to do my 4 hr bumps?