The rules in the FITA book take account of the fact that with FITA now running Para-Archery the rules have had to be modified to take this into account. The only way to be, officially, eligible to shoot using a release on a
recurve bow would be for the person to have been classified with a disability. There is nothing though to stop you shooting unofficially and using one the only problem being that you would more than likely be ineligible for any awards. As an aside to this the norm within Para-Archery is those archers with classifiable loss of upper limb function shoot within the ARW1 class which is
recurve-wheelchair(so lower limb dysfunction also)-recurve, but they are allowed to shoot a
compound limited style, no peep or scope, but use a release aid. For those, like me, who have lower limb problems but the uppers aren't bad enough to classify, it's a case of shooting unlimited
compound.
Hope your finger heals enough to allow you to shoot the style you want though!