I'm on my way :p

@emc2 Hmm that's a pity. I could not find why specifically it was assigned to that pin other than that it is a MySensor default, so I thought maybe it can be changed (manually).

I wanted to use the WEMOS system for my nodes, not as the gateway. But if it is not possible to free up D1 & D2, there is no benefit in using them. This board is the best I could find, I would order them if D2 is freed for D4. Could you make it possible to use one of both (with a jumper of some sort) so it is compatible with either WEMOS shields, or the MySensor defaults?

Is it possible to free D2 on the WEMOS, it is used on most WEMOS shields for I2C.