best is to use rotational proxy along with gologin like multi-login anti-detect browserBlueStack > Macro > Create > Reset Proxy > Repeat Process
In this process you can gather App password easily and disable spam filters.
Good Luck
for anti-detect browser , use login. for proxy you have to search it yourself, no one is going to tell you what proxy works good for gmail.
Gmail costs around 0.09$ for mix country, and 0.18$ for USA Gmail, you can look it in tekustore, google it
Are you sure it will work? From my experience, i can only say, your answer is incomplete.