We have a requirement for a minimum Xamarin.Forms version and it is stated here: System Requirements
. That is the version our source is built against, still, you could use the Telerik controls with more recent releases of Xamarin.Forms without a problem.
If you experience any concrete issues with Xamarin.Forms 4, please let me know, so we could investigate and evaluate them.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items