I don’t know how large is your config, it’s a little different if it has 100 lines or 10000. I generally prefer to open exported config in text editor and transfer it manually to new router, one part after another (cut from text file, paste in router’s terminal). It may take a little more time, but this way I notice various leftovers that can be cleaned up, I can make small changes as required, etc, so it’s worth it for me. About versions, the closer they are, the less likely there will be incompatibilites. On the other hand, RouterOS config does not change in backward incompatible way too often. But sometimes it does happen and tranfering it by parts helps, because it doesn’t just die in the middle, you see the problem immediately and you can fix it.
Well logically it makes sense to transfer a config from version X to a router with version X, and then upgrade the router packages after (less confusing).
Unless config from version X is compromised/hacked and then one is copying garbage over…
Although a bit slow, using config file and terminal is error free to get all the info over to the other router.
Especially for static dhcp leases or address lists etc… I make enough mistakes to appreciate this method.
I discovered the COMPARE plugin for notepad ++ which is really practical!!