I did try to remove 1 and 2 hashboards, but the problem is that each hashboard run at minimun 6-700w and they overheat with silent fans. If i could split the heat over all 3 board i could keep them cool and silent.

I have a S9 with braiins, and on the S9 i can underclock each board down to +-130w and i'm able to keep it cool at 400w total spreading the heat over all 3 boards. Enough to help keep my bathroom warm.

If the firmware on the S19j Pro would work the same as on the S9 i should be able to underclock it down to under 1000w on all 3 boards given that the S19J Pro have a normal power usage at 3.2Kw compared to the S9 at 1.4Kw. In theory..