The pillows of the hybrid are made to pop out -- to allow switching the sizes.
Merely taping over the ports where the pillows are inserted would be very easy to accomplish (from the inside).
Using the mask with an ALMOST stopped up nose was very tricky for me -- my nose wouldn't allow enough air but allowed just enough to make it seem possible and keep me from breathing easily through my mouth.
It woke me many times during the night to allow consciously switching my breathing from mouth to nose and the whistling through my nose was so loud that alone was keeping me awake.
I tried quite a few things (quick ideas, not getting up and fixing the mask as described) trying to BLOCK my nose FULLY to just allow (or even force) breathing through the mouth alone.
There was a similar effect (but worse) with the F & P Oracle Oral mask. This was worse because the Oracle doesn't cover or block the nose so being able to breath through the nose "a little" was very difficult to deal with.
(And the stupid nose plugs included with the Oracle were entirely insufficient and unworkable for me -- also reported by a lot of other people.)
I strongly suspect the Hybrid with the pillow ports closed will make a MUCH better "oral only" mask than the Oracle does, and it will always have the flexibility to put the nasal pillows back on and use it that way, as a Pillow/Oral mask.
Sleep study AHI: 49 RDI: 60 -- APAP 10-11 w/AHI: 1.5 avg for 7-days (up due likely to hip replacement recovery)
"We can all breathe together or we will all suffocate alone."