You were able to do jumps with the blades secured to the boots only with tape, no screws at all (not even the so-called temporary-mount screws)?
Yup. Often I would go a month or more with my skates covered in strapping tape, moving the blade ever so slightly until I found my 'sweet spot'-which, if you looked at it, was in no way centered on the boot. Normally I preferred my blades slightly inside of center on the right foot only, giving me an easier outside edge I suspect.