bawnerif i am reading this correctly, it's just picking up a medigun to cancel your current uber and save some % like this?
This was removed in the current season in europe.
it is, and tf2-comp-fixes addresses this with the following feature:
When enabled with sm_empty_active_ubercharges_when_dropped 1, mediguns that are dropped while the ubercharge is active will be emptied.
This prevents the trick of swapping mediguns while ubercharged to conserve some of the charge.
the argument is that activating an ubercharge is a transaction that implies the complete consumption of the ubercharge, whether it's used efficiently or not.
with that plugin, the aspect of the dead ringer doesn't matter much.
the theory crafting about demoman stickies seems very silly to me.