How to fully cache a file that plex is accessing

I'm currently using rclone mount to access files in my google drive. If plex accesses this file, does it fully download it and cache it? I initially had a problem when I opened a file from plex, paused for a short amount of time, and then tried to resume playing. I think it had to restart "downloading" the file so i had to wait for a little extra time.

Is there a way to cache currently accessed files and leave them there for a specified time (for example, uncache it if it hasn't been accessed in x {minutes, hours, days, etc})

Well yes and no.

You can use the cache backend and have disk set aside to store the chunks and keep them for a long period of time, but there isn't a concept a file only chunks.

For streaming, I find it faster to not use the cache backend and let it do its thing. The pause could be plex analyzing the file or plex analyzing and transcoding the file.

I get playback to start in 1-3 seconds on average as I direct play everything.

For resume play, I use a timeout 1h value in my mount to hit that particular issue.

which flag is that?

edit: found it.