Are you allowed to

I’ve read your posts and I’m giving you a warning as a moderator

How about as a moderator you curb the off topic trash talk and take it to personal messages if you really have a problem with people writing answers and asking legitimate questions of the legal team on the forum?

My understanding is that Quixel’s stuff can be used in UE4 based games and nothing else.

lets be clear , you are only allowed ot use assets you purchased inside the unreal engine, you cant take htem out and put them in untiy without a new liscense also if you have anyone work on stuff thats fine as long as its brought back into the engine under you , as in your project and then you and only you get rights to sell if its a game…they if they wanted to need to buy said assets if they wanted rights to sell and youd have to agree between you about selling rights of co made items

also im sure some kinda lawyer then or written or email agreement needs ot be spelled out.

pretty sure this is how you can do all you want with a few friends that might pull a texture out into say 3rd party software and bring back into the engine. ( note if 3rd party software prohibits you doing this then you cant use it )

The marketplace has entierly different licensing.
You should probably read up on it if your asking about that specifically.

The licensing for quixel was changed during the epic merger.
There’s still the possibility of having different licensing if you bought assets from them over 2 years ago / whatever licensing they were using at the time would be what you are technically bound by.
And good luck finding a copy unless you happened to save it… In the end, it was probably still some sort of licensing. As licensing goes, you aren’t usually granted resell permissions.

The thing with marketplace and people stealing and reselling your assets after one purchase is that it happens, it’s obviously illegal, and epic doesn’t give a sh*t about it.
If anything they encourage it by not protecting our rights with lawsuits and DMCA requests against known offenders. That’s out of topic in this discussion though, even if worth a mention.