Hello. I almost exclusively play Mobile pre-hardmode, which means I don't have to worry about autoswing. Autoswing is one of those weird things that makes a big difference in Desktop/laptop/console and is completely negligible in Mobile. With that in mind, I actually found almost no problems. Almost all the swords with autoswing have some other unique feature, such as increased crit chance for the katana or increased knockback for the slap hand. As I said, I don't really play hardmode, as in the last time I did hardmode was several years ago when the Mobile version was its own animal and has since received several major balancing updates. However, I do know that once you get the mechanical glove, which (I think) is an early hardmode item, autoswing becomes negligible. That means that I don't have to worry about a hardmode item that only benefits from autoswing, as you could just don the mechanical glove and ignore it, and any of those items are a problem already. Long story short, I think you should give all weapons autoswing. This is more of an annoyance than a major gameplay issue anyways, and it's not like there are many weapons that's sole existance is based on autoswing, otherwise, DR probably would have never re-added it. Thanks!
Edit: Other types of weapons (ranged, flail, etc.) require more precision and less stabby stabby, so I'm fine with full autoswing only applying to swords and whips