With the new file window ribbon it shows me only 3 of my 7 favorites icons. Is this deliberately restricted?
There is enought room.
No. If there is not enough room, the icons automatically wrap into a second row.
Are the favorites not added or are they just invisible (no icon shown but space allocated and clickable)? Hover the mouse over the space right of the last icon. Any warnings in the log file?
Icons not there.
No W> in log file. Nor E>.
If I create a new icon it does not show (but is visible if I turn off experimental mode).
I have diagnosed a bug together with another user since this morning and fixed it.
The favorites you don't see should be "normal" favorites, not application or App Store favorites. Under some conditions, the ribbon does not detect the user-defined or stock icons (from the drop-down list) and does not add the buttons.
This has been resolved for the next release (release note #2157).
The normal toolbar should show all your icons.