So this is just an idea, it might work it might not but it totally needs someone to test it out and fix whatever I might say that might not work.
The Winning 2 remote has a spare channel, that channel is in this case used as a switch. (CH2)
The remote has a button, as first I had the idea that it would be used to sync but no! When you hold it in for 5 seconds it makes the channel switch state aka it acts as a switch.
So if we added that with an Anti-Spark Switch, removed the switch used the channel.
Found a way to give the receiver power even when the board is off, we should be good.
Of course, it’s not as easy as that, but that’s just the general idea of it.