Will this connection between EA and Python via sockets work within the MT4 strategy tester?

Oh, I see. It will work in strategy tester, but the connection (via TCP) is slower when compared with simple socket connections, so you have manipulated the OnTick functionality so that it only fires when a new bar is created. Correct?

That may work if the strategy only looks at closed candles and not at every tick.

Have you thought of creating an MT5 version?

MT4 has a serious limitation in backtesting due it using only one core even if 24 are available on your computer.