It's a common issue. If you breathe through your mouth at night, it's often because you can't get enough air because your airway is compromised. Once you add PAP, that problem goes away, and many people can revert to nasal breathing.
There is an adjustment period, turbinates can swell up from the extra airflow, and it might be uncomfortable for a while. And some people have such awful septum deviations that they're breathing through a straw. But most people are fine.
I assumed that my need for CPAP was mostly because I'm old and overweight. But I've always been a mouth breather even when I wasn't overweight, so it seems it could be more than my weight issues.
Untreated sleep apnea is often a cause of overweight. Being obese can contribute to sleep apnea, but unless you're extremely obese, it's rarely the cause.
That was my plan, I expected to need the tape. But I tried it without the tape and found it unnecessary. Have you tried without the tape? Worth a try if you haven't.
The morning after my first real sleep in ~5 years was an unreal improvement. It felt like I was snatched from my death bed and back to normal.
I use the nostril mask, and it doesn't really bother me. The full face mask experience is a lot worse.
PS Technically, it blows!