CPAP Settings Full Face vs Nasal - Same?

Hello everyone,,
I was fitted for and have been using a full face F&P Vitera Mask for about 8 months. When I awake in the morning my eyes are puffy and some areas around the eyes seem less sensitive to touch (sort of a numbness). For a good portion of the morning there is what feels like sinus pressure around the eyes which wears off during the day. I've gotten the headband straps adjusted so the mask is comfortable and not too tight and I've been able to maintain mostly a 100% mask fit with AHI numbers of about 1.9 - 2.1 for most nights. When I had my sleep study with titration the hospital gave me the ResMed Airfit N20 nasal mask, which for the study didn't work well as I'm a mouth breather. With the full face mask I've been using a chin strap to hold my mouth closed as I was having a very dry mouth. I'm thinking of trying the nasal mask along with the chin strap, but I'm not sure if the CPAP machine ( Dreamstation) may need a setting changed to accommodate a different style mask. The Dreamstation does have a 'Mask Type' setting, but this is currently set to 'OFF' and the numbered settings seem to be for the Philips Resperonics Dreamwear series of masks. I'm guessing the pressure would remain at 8-20 cm/H2O as prescribed, but not sure about the Flex setting (C-Flex, C-Flex+, A-Flex, or Bi-Flex) as I'm not clear on its function. Currently set at 'C-Flex' for Auto CPAP. The humidifier is presently set at max.

Should I be good to go with no setting changes or is there something I should take a look at?

Mask type setting is just for Respironics masks. When using non Respironics masks we are told to just turn it off. It's not an ultra critical setting as it really pertains to resistance anyway.

Use whatever Flex setting is simply the most comfortable setting for you to use in terms of matching your own respiration pattern.
It's a comfort setting. I usually suggest that people try all the settings and simply pick one that feels the best to them.
I didn't care for C Flex as I couldn't tell it did anything but I really liked A Flex. It's all individual preference. Flex is more of a timing issue anyway...pick what feels best to you and don't worry about it.

There is no urgent need to change the settings when changing mask types.