Ok, thanks (don’t remember this was announced / reminded recently, but I may have missed it).
So, it seems I’m doomed for a full manual OS R or T install and the many hours and energy to invest for that 
, as no OTA exists for dev builds IIUC.
Do you have an advice about which build & version I should choose ? (seems there’s stable R, dev R and dev T available for 1.16 AFAICS).
Thanks.