And again they are starting with 5e, ffs.

A shopping trip can kill half a session if it’s been a while.

Do you really have fun running a session like that? Me and my players would die of boredom.

Our Sorcerer knew Wish, but the player knew better than to try something like wishing to get to the lowest level of Hell, because on the meta level they wanted to play through this adventure, not to cheese.

The biggest challenge during Tier 4 is still resource attrition. Let them use their big spells, but don’t let them rest. The best challenge you can give them at this point is to make a multi-session-spanning dungeon-like structure.

An example from my previous campaign: heroes needed to get to the lowest level of Hell, but they needed to transit through every one of them in process. Enemies were everywhere, and places for rest were virtually nonexisting. I think they had like 1 long rest in four months of play during T4, and it actually was hard for them.

When I did play 5e IRL, I used Ard sheets, tweaking them in Photoshop or Illustrator whenever needed.

The worst thing is Bob doesn’t know he wants to play something other than D&D.