The P30i has a standard frame and a small frame. In I couldn't get the standard frame to work with any size pillow. The small frame seems a little better but I have yet to be able to sleep through the night with the P30i, so I am also searching for the magic. Last night I switched between 4 different masks to make it through the night. And then I wonder why I'm so tired... It takes time to find the right mask. Here's one I keep resorting to when all else fails:

Frame for Dreamwear Nasal/Gel/Full Face: Medium Size https://www.amazon.com/dp/B07L6P5WCD/ref=cm_sw_r_apan_glt_i_09NZXQA91N35GCBV8F0R With 2021 Version Replacement Elbow/Swivel for Dream Wear Nasal Mask for CPAP Users https://www.amazon.com/dp/B08TRCV4GH/ref=cm_sw_r_apan_glt_i_9X5TTX67QEV013YF9ECV And Philips Respironics DreamWear Nasal Cushion (Medium) https://www.amazon.com/dp/B01CLE3DRY/ref=cm_sw_r_apan_glt_i_AG1RGTDRAANZZ8TDKRYH

Beware I'm told this only works for 50 percent of people and can leak too much for others. Also both the frame and the nasal cushion comes in three different sizes so it can be a bit of hivt or miss. I was desperate and got lucky, what I ordered fit. Then I found out that the same frame fits nasal pillows (I haven't tried) and a small version of full face mask (I did try). If you don't mind spending the money it's nice to have choices.

PS: I also tried the P30i frame with the n30i nasal cushions but for me it doesn't work at all, leaks like crazy in all combination of sizes.