I mean, you can do both in either configuration, it's just slower (for both things). But I see what you mean. I just find that I don't need his tilts specifically as a reaction to something, only as a planned action, which I end up doing with the left stick most of the time anyways. We'll see if I end up doing more tilts on reaction with Doc as time goes, but for now the only thing I personally feel the need to react with is up smash and occasionally down smash to cover ledge rolls. I am fast enough with left stick 90% of the time, but up-smash OOS on faster aerials feels easier with right stick for me. I still refer tilt stick for basically every single other character that I play (roughly one third of the cast at this point) so I definitely see tilt stick as the overall superior option for most of my characters. I might even end up bringing it back for Doc, too, but it doesn't hurt to at least try different schemes for different characters.