Question about Mega file limits: 8TB across 6 million files

I need to back up about 8TB of data consisting of roughly 6 million small files. I'm considering Mega, but I have technical concerns about their client-side file tree decryption.

I suspect that with 6 million files, the web UI might just crash or fail to load entirely due to browser RAM limits.

Has anyone stored a similar number of files there? Can the web UI handle it, or is the desktop sync app the only way (and does the app even survive this amount)?