I started my tailwheel conversion at Clacton last August,
almost immediatley after I got my PPL licence,well 6.5 hours later .
It took me around 10 hrs over a two week period due to weather to get my tailwheel sign off , I was fortunate to buy a share in a local L4 Cub straight away, and now have around 11 hours on that.
I would say do it as soon as you think you are ready.
It started off seeming almost impossible because of the "massive" control inputs I put in on the ground.
But it does eventually click and then your inputs will be gentle and almost non-existent but non-stop!
Have fun
Lister