PowerZone Noob

Hi, everyone! I've had my Peloton bike for a few years now, but am trying to get into the PowerZone rides as I've heard great things about them from members. Yesterday, I hopped into a 30 minute endurance ride with Olivia (Zones 2 and 3) and it seemed too easy. I then discovered that I should have taken an FTP test first, so I did a 20 minute test to get a more accurate FTP value. I tried the 30 minute endurance ride again today and while I felt it worked me a little better, I still felt like I should have gotten more out of it I guess? I think I did the test right. I did realize maybe a little late into it that I should've been progressively working from Zone 4 up, so that at the end of the 20 minutes I was at max capacity. I did hit Zone 7 for about the last 3 minutes or so. I ended up with an FTP of 248. I'm 6'3" 220 lbs. Does that sound like an FTP that would be accurate for someone my size? I know there's a number of factors that contribute to that, but I wanted to see if I'm in the right ball park. Thank you!