What is best practices for mounting Backblaze & Google drive

Hello all:
I am running a website with huge users database with a lot for uploads.
My current server has a 6 TBs drive which almost close to full.
I thought that i may use one of the cloud providers (Google drive or Backblaze) to auto mount it to my system and store my files on cloud and let my server hard drive work as a cache layer between my users and the cloud service.
I already have an unlimited edu accounts on google drive but i am afraid of google drive access rate errors.
I need to know which one is better between the above provider and what is best configs to mount each one for best performance and latency.
My current server has a 16 core , 32 GB ram and 6 TBs hard drive.