I also do not use TDC in S boats unless playing in 43(some S boats had TDC installed in 43) Not that hard just have to update info until the moment you fire since no PK.
Looking forward to trying this out but scared it might do something to TMO and do not want to do that, oh the agony
After reading some books on S boats, understood what crappy conditions the Pigboat sailors lived and fought it, gave me a whole new respect.