Usually, people keep their @handles private.
But to answer your question, when using 1-5 accounts, which is allowed per them there is 0 upside to using proxy, can even argue there is downside
Verify your profile. Make a list of 100 bigger accounts with good reply engagement that can be related to your "niche" and just reply to all as soon as they post with something relevant, funny, meme, interesting or whatnot. 1st come 1st served thing.
Reply 50-100 times per day for xx amount of days and you will be growing on your own. You don't need anything else, just grind