I honestly don't know the difference between how a relay like OP talks about or a mofset works, but this is the one I've installed on my Tevo and what's always recommended for other printers like the A8 or Maker Select.

Personally, I ran both the positive and negative wires through the mofset (rather than just the positive like in OP's picture). So it's more like this.

I installed this one: https://www.amazon.com/dp/B01HEQVQAK/ref=cm_sw_r_cp_apa_F7zKBbSQY2CMQ

Few months no problems. Heats up very quickly. Provides very steady temps. Hardest part of doing the mod is getting the board to slide out and not snag a wire.