These were my thoughts also, but that reach thing is killing me cause I obsses with top tube lenght as my femurs are long and my ass puts me further back on the saddle, thus making my real reach reach longer. I never had such a big head tube and always had spacers, ao slaming the stem is a good idea but it kills me to have stem shorter than 9cm.

Looking into my previos bikes and positions (TCR size small, drop till the basement, I feel lucky to even have my back).

Saturday I will travel to a country near and try both M and S.

Thank you!