What type of tom holder is on there? Pictures would help me give you an intelligent answer. Of course, I am not a fan of placing a mounted tom on a snare stand or hanging it from a cymbal stand.

Its the Set O Matic Double Holder (with the two little nubbys on it). Im noticing it kills the resonance of the tom.

Both of my 70s Slingy kits I have my rack tom mounted on either a snare stand or cymbal stand. I left the mount on the bass drum. It sticks out a little but I think it looks better than 4 small holes, and 1 big hole on the drum if ya ask me. Same goes with the mount on the tom itself...

I just recently noticed that my 3 ply Ludwig 13" tom also resonates a lot more on a snare stand, then on the stock mount on the bass drum. I left the mount on the tom and cleverly store my drum key in the hole! I also left the rail consolette on the bass drum and use that as my cowbell mount! Just being creative with what I have....

Noticing more resonance from a tom placed on a snare stand or hanging from a cymbal stand is subjective. The tom is merely repositioned, thereby perceived to sound different to the person behind the drum set. I will not doubt that there can also be a change in resonance, albeit insignificant. From out front, the tom will sound the same to 99.9999999% of anyone hearing it if it is tensioned the same on the tom holder, a snare stand, or hanging from a cymbal stand. Recording situations might be more critical to minute changes in resonance. But, we all know that many recording engineers would choose to make any drums sound like wet cardboard boxes if left to their own devices. These are my very biased opinions gleaned from over 50 years of playing drum sets in all types of venues, and doing a bit of playing on recording sessions.