Oh, there is 4.0 for the Pro¹. Bundyo was keen to update very early in Feb even afair. You could anytime OTA from 3.4 to 4.0 nowadays.
The images to flash 4.0 are not working currently as i had to find out this week when reflashing my prawn.
During flashing around yesterday i even managed to have 4.1 but that is not advised since the Pro¹ hardware adaption needs to be reworked.
All in all i am still relatively satisfied.