Charlie wrote:

The babies have starting feathering now (3 years old) but as you say I
have grown quicker palms!

I've grown about several Phoenix species and hybrids over the years
and rupicola seems unique in the way it continues to produce a broad
terminal leaf blade on adult (feathered) leaves for quite a while.
Other Phoenix develop adult fully pinnate leaves after just a couple
of years, but this one stays at the half way stage for a couple of
years at least. That characteristic makes it attractive and
interesting even as a small plant - which is just as well because it
remains small for quite a long time!