I’ve had a few Unique 16” loons. They were more resilient than I expected, though I was reluctant to push my luck with the size. They felt
wonderful, though, especially when they soften a bit. My best guess is that you’re fine as long as you don’t make them very tight, which seems to go against what you’re looking for.
Compared with U16”, Q16s are more durable but I don’t think they get as soft. Q16s tend to get tight as they approach a risky size, so it’s difficult to accidentally BTP one. They can soften with repeated inflation. As a nonpopper, you’re probably safer with Q16s if size is what you’re after.
I prefer TT17” over Q16” because I find Tuf-Tex balloons stretch easier past their rates size; plus the neck is superior. U16” tend to also stretch nicely, but TT17” are safer for nonpoppers.
I don’t think I’ve had Belbal 14” unless that was the freebie from B.U. (though I suspect not), but I’ve had Belbal 24” (B250) and Belbal 36” (B350), and I think they’re a dream for nonpoppers.

The B350 can get quite large, or you can keep it smaller and it’s a fun ride. The neck is underwhelming, and it can take time to soften, but it’s very fun. Both large Belbals are very durable, so you should enjoy them.