I know you can get Maple flooring that's soft. Plus, most flooring that I've seen / worked-with isn't beveled, or eased. Square edge is more expensive because the mill has to be more quaility-conscience. I dont' know of a retailer that doesn't offer Eased and Square flooring. (Maybe one particular 'model' is eased-only but there are other models that are just-as-well square-only.) So, I wouldn't say a pre-finished floor is any different than a finished one, based on being eased or square.
As for using the 'soft' maple for flooring, there are a lot of mfgrs. that make it. Lumber & Mill Yards. (Search the page for floor and you'll find what wood is used.) The listing is for the US and around the world.
As I mentioned previously, a factory-finished floor (eased or square) is stained and finished under controlled conditions. MAYBE you can get 4 coats of poly to 'do the job' in the home (if you're having the floor finished on-site) but it doesn't beat the look and feel of 6, 7, or even 8 coats that the factory can do. I'm not bashing any pro that installs unfinished flooring and does on-site finish; I'm simply saying that after so many coats of poly being applied on-site, the poly gets soft and gummy. I've just never seen it done on-site with 5 or more coats. And 6, 7, and 8 coats help with the wear and protection and maintenance and longevity of the floor. Heck, at one time, ALL hardwood floors were finished on-site. But not with as many coats as the factorys put on pre-finished flooring. It is less expensive in the long run and that's what a hardwood floor is suppose to do - be around in the long run.
I agree - Oak vs. Maple is a personal preference. My best to ya and hope this helps.