I have about 200 hours Pitts S1 S. I always wanted a Pitts etc
My conversion route was not deliberate, I got into a Pitts S1 only when one became available to buy at the right time/price etc.
I did 5 hours Citabria/Decathlon, then 300 ish hours Wittman Tailwind interspersed with some S-2A time on G-WREN at NSF.
For me, the Wittman Tailwind hours were very useful because it is also a fast landing tail dragger, short and squirelly with powerful/sensitive controls. i.e. I was very used to Pitts speed approaches, recognising excessive sink and keeping it straight and not overcontrolling.
Once in a Pitts S1, all that was left was being able to do it all within the runway boundaries without any forward vision - which is what makes the last bit of the landing (speed, attitude, direction, height) so very interesting.
So I'd say Citabria/Cub etc time is not that useful after about the first 5 hours, but what is useful is something fast and demanding.
e.g. unless you have a Tailwind or similar - bash round the circuit in a hired S2 until the owner lets you go solo, then do quite a bit more solo S2 until you get into your own baby.
Petes1s