No it is not tubular specific but it comes recommended in a YouTube by “Caden” an Australian wheel builder who swears by this (generic version) of 3M double sided tape. I’ll double check the width and marking on the tape. In the video he explains the advantages of being able to position your tubular tire properly before peeling back the wax paper then inflating the tire.

As as far as my wider than normal Velocity Major Tom rims, I’ll try different tires and hopefully find some that are road specific that don’t end up with a gap at the base tape. 27 to 30 mm would be ideal and hopefully clear whichever frame I ultimately run these on.