Hiding from google/gmail?

If I wanted to run automation within 100 gmails accounts (performing different actions like replying to emails) — what are some ways to avoid the automation being detected?
I want these accounts to appear as authentic as possible, so I’ve considered running them on virtual machines & binding each to its own residential IP address.
I worry that Puppeteer would be easily detected, and Selenium may be as well.

Anyone have experience in this area?
Looking for opinions, other options that I may not have considered, and ideally a solution that could be easily scaled beyond 100 accounts.

Thx

Don't run all of them on the same IP.
Generate unique fingerprints.
If you use multiple VMs make sure they have different settings like screen resolution, language, software, browsers to help in generating unique fingerprints.
Use variety/random of actions in your bot to look like a real person.