Decaf beans are harder to roast well (IMO) so it tends to be that the mass distributed ones won’t be great since they’re in less demand. You can find small locals that do decaf runs sometimes, or order green beans and do it yourself. Remember, darker means less caffeine, so if you’re pulling medium roast beans and have no good decaf source, try something dark that you can tolerate and see whether it helps
More complete overview below, but basically, it can move faster through phases, can’t be judged as well by color, and can reach crack at lower temperatures. It’s totally possible to get a great outcome! Dialing it in is the fun IMO Link