doublevr It's by far the lowest in the industry and you only get 150 videos if you use every download window to the max. With many studios exclusive on SLR we are getting to a point where it gets hard to download even those exclusives without a lot of micro management.
Second lowest should be VRBangers with 10 downloads per day (if they haven't changed that in the recent years) and then VRPorn with 20 downloads per day. POVR/WankzVR has about 15 dowloads full speed and 2MB/s after that. Maybe more bandwidth reduction at 30-50 videos per day.
BadoinkVR, 18VR, VR Cosplay X and KinkVR don't have a limit, but download links get invalid after a few hours, so you can't use download managers that easily.
Virtual Taboo, DarkRoom and VirtualRealPorn don't have limits.
It's not only about the total amount per year, but also about convenience. You've noticed that problem as well, that's why you did 30 per 144 hours instead of 5 per day. But even that will be annoying if we want to download more in vacation weeks or if we discover a new studio and want to catch up on past releases.