I have PSTV 3.60 and last week I tried to enter PSN store and it said I must update (but I don't remember if I launched HENkaku before trying, HENkaku enables to enter PSN store even with 3.60 firmware ?)
If you didn't load Henkaku before trying the load the store it will prompt you to update just like it would any console with what Sony considers outdated firmware.
Fully updated Henkaku/Vitashell worked fine last I checked and I'd assume we'd be hearing about it bigly if something had changed.