Personally, I find tuning is much easier with an even tillered bow shooting 3 under if I am shooting off the shelf. I have to run an unusually high nock point with bows that have a substantial amount of positive tiller. The bows ive had with positive tiller shoot perfect with split finger but give me fits shooting 3 under. This could be an effect of something wrong with my shooting whether its grip pressure, release, shooting a glove, etc but I dont know. Ive been told by several bowyers tiller really shouldnt matter that much but for me, for whatever reason, even tiller is what works best. Alternatively, if I am shooting an elevated rest I can get away with a little positive tiller as that allows normal arrow positive with a higher nock point.
If you are getting good arrow flight and consistently hitting your target then keep it up. No reason to worry about something that is not causing any issues.