UB is only one class of error though. I get nervous when people talk about re-writing battle hardened code which has been used - and reviewed by the community - for decades because there are going to be many subtleties and edge cases which are not immediately apparent for any developer attempting a re-implementation.
There already are a few indie Morrowind clones like Dread Delusion that I’ve had my eye on. Not sure what elements will have been compromised by the budget but keen to give it a go after payday next week.