Hi Philippe,
JCE is visible and can be used, but first you have to:
- Choose JCE as main editor in System > Global Configuration > Default Editor > JCE > Save & Close
- In Text addon on toolbar click "..." icon then click "System Editor" [<>]

and you will see JCE toolbar, as here. I use JCE in SPPB very often (screenshot from my private site)

I also recommend to reduce number of icons from JCE toolbar (in JCE Profiles > Features & Layout), there are too many of them, and most editors will not use them all.
