I'd tread carefully here with blindly replacing boards - the problem is not (as I understand it) known to be with that card at this time. That is what OP is asking about and unfortunately I don't know enough about that card to understand the protocol between itself and the (modified) spindle control card in the mill (the same kit, even if OEM with SIEG, requires a modified micro controller on the spindle control card).

This link provides a really interesting bit of reverse engineering which explains a bit about the protocol used on the "LMS" board (aka Sieg board).

https://blog.familjenjonsson.org/blo...olant-control/

I'm about to head to my SX2.7 and see if this is similar to the touch-panel interface (nothing is ever that easy! and I fear the LMS interface will be different)