You can shoot a recurve with a release if you want to. I don't know how well it would it work, but I have done it. Axle to Axle length really doesn't determine if you use a release until you get to short bow. The shorter axle to axle bows are hard to shoot with fingers and some are so short a string loop is even better. However a longer ATA bow can be shot either way.

Like said above you would want the proper rest for it, like a prong rest or something that takes up shock from the bottom. Some older bows don't enough shelf room for this kind of rest, maybe that is your case? Finger shooters need a rest that absorbs shock from the side because the arrow flexes from side to side.

Paul