Thanks for the answerHow many is a lot of? Within the same browser instance it can be risky, unless you use something like MultiLogin, which is not exactly cheap. For that money, you can get a multithreaded Twitter bot with proxy support.
If you want something free, try Firefox Portable, make an instance for each Twitter account with its own set of proxies and cookies and look into browser fingerprinting (user agent switcher, canvas fingerprint changer, webrtc leak prevent).
That's what i'm doing. ThanksIf you don't want to spend, just use the portable browsers version. Make sure to install the important privacy related add-ons