Hello @trapexit and welcome to the forum!
In 20-20 hindsight, starting with a small initial backup (for example, the most important data) might have gotten an initial file list quickly, then you could add additional folders. Adding in chunks might still be best because you will have a more periodic upload of the relevant info, basically forced by this upload plan…
There’s in theory a synthetic filelist uploaded, when resuming an interrupted backup, which creates a file list based on the previous backup plus progress before interruption. I suspect it has a bug explained here and I’m not certain even a bug-free version would handle the special case of an interrupted initial backup, but starting from there seems like a possible reasonable path to make recovery from interruptions better.