I don’t feel that way as outside naturally will have more over threshold efforts, so I find inside workouts to be easier.
I’ve been using average power for the 2-hour % FTP, but if calculating off NP then its much higher. Here is a 98% 2hour-NP-to-FTP:
and a 99% 2hour-NP-to-FTP:
To my eyes it seems silly to use NP for these calculations. Using average power gives 88% and 91%. Those were selected using 2 hours on the PDC and you can see that first one only had 107 seconds of downtime which in my humble opinion was more than offset by ~8 anaerobic efforts.