Huh? News to me. More horse stuff as far as I can tell. Why would track ends matter at all? They do not come anywhere near the valve stem. Rim width being a problem... yes drop out style..NEVER.

My Ralligh has 27 presta drilled Mavic MA40's. 27x1 1/4tube is interchangeable with a 700x32 Most tubes in that size are marked with both sizes. 700x23 will fit a 27x1 1/8.

The only time you must use a presta is if the rims section width is too narrow. A rim 20mm wide is plenty wide enough for either and it comes down to personal preference. If you like Scrhader better then drill the rim out enough to fit them.

What I do like about Presta is the threaded stem keeping you from having to hold it from pushing into the rim. Most of my bikes wear presta to Schrader adapters so that I don't ruin another valve. I don't even take them off and tighten the Presta on two of my bikes.