The marketplace team has made it a standard. You’re better off following this standard ahead of time, if you want a smooth submission.
Same thing for plugging a 0 constant into metallic – just do it, because it will save you the time and aggravation.
It’s not their job to change the way they work to suit you; it’s their job to enforce standard ways of working that works for them and the store, and your job to follow those methods.
Second: I bought the pack a long time ago. At that time, it had huge cracks in the lava landscape; it was not a continuous mesh and not usable for any game.
Is that actually fixed? Because that sounds like one of the reasons for the refund.
The landscapes also weren’t really set up to work well for any particular game – very few areas were truly level, and there weren’t really any areas that were set up with playable canyons, overlooks, etc. Gameplay typically requires landscapes sculptured much more deterministically than a standard topographic map from the earth.