Using mount to read a large zip file (with Python)

I am not sure if this is on topic or off but I am thinking through reading a large zipfile with a read-only mount using Python.

My plan is to use rclone mount with --read-only. I think I can get away with no-cache (see below) since it is just reading but it should be seeking. Part of the problem is, rclone mount with full cache uses sparse files but, at least as I understand it, they are zeroed out files. (is that correct? Its how it looks on the file-system but that may be wrong).

And then I will browse and extract via Python's zipfile module.

Has anyone else tried this? Does anyone have any experience with these and know what to expect?

BTW, just to avoid an XY problem, I am trying to read one or two files from a large Backblaze Snapshot stored in B2. I am trying to (a) avoid paying egress to download the whole thing but more importantly, (b) trying to do what I can on a VPS with limited storage.