The method you describe is how I save many tropical plants sold as annuals. Take cuttings for winter, plant outside for summer. Repeat in the fall. Coleus is a classic example of this. Also works well for many house plants, especially the creeping, non-woody kinds. When they look ratty, it's usually easier to start a new pot of cuttings than try to repot/rehabilitate the roots. Tradescantia zebrina (WJ) is the classic example of this. Theoretical discussions can be interesting, but not necessarily helpful across all kinds of plants. What are you propagating?

I have best luck with half matured wood, mid to late June. However, I haven't done sugar maple, so am not sure how well that will work.

HelpMeFind is really useful, but only if the rose has been listed there under the name it's been sold under; sometimes with older, out of patent roses the wholesaler will stick an unregistered name on known varieties to sell them. These tend to be 'body bag' roses, or the cheaper plants at big box stores. https://www.helpmefind.com/rose/plants.php Most have a patent date on them, if they are patented (some antiques obviously aren't and never were). I want to say it's 20 years from when issued before the patent expires, but others could say for certain.

I have but before doing so, I'd like to know whether its worth taking cuttings from a tree that was badly damaged and might be diseased. I also want to know if fire blight or whatever disease thats killing off tips of the branches are affecting the whole tree in general or just the branches that are affected. If its the latter, I can safely take cuttings from a healthy branch and not have to worry about the rooted cutting having fire blight.