If you are using your home connection, then you are losing against seedbox users. Seedbox has better peering.
Private Tracker. Just do the MAX trial and download 720p using streamfab.
Even if it's 720p should beat the dvdrip version so just download it using streamfab.
The 1080p if it's available on MAX then it will come eventually. I already saw 720p web-dl.
If you always found what you were looking for in public trackers, then private trackers have no advantages for you other than download speed.
some tubi contents are not drm protected so you can easily download them with yt-dlp as already mentioned.. If you are using firefox there is a drm (drm protected) icon next to https.