Practice tips for accurate finger placement on a Bb

I am new to tin whistle playing and need some help. I have relatively short fingers and have to use piper’s grip on a Bb. Even with piper’s grip my right hand pinky is not long enough to be used as an anchor. When I lift all right hand fingers off and then have to place them down to sound the Bb note I have trouble placing the fingers accurately. For example to transition from Eb to Bb. Other than practice more, does anyone have any suggestions on other techniques to try? Can I anchor with the ring finger covering the Bb hole? I don’t have this problem with the standard D whistle. Thank in advance.

Get (or improvise, if you’re handy at such things) a thumbrest for the right hand.