Using a Bump to Prefocus

I'm setting up an Awards show on ELE2 that doesn't lend itself to a regular cue stack. I like to set the various 'positions' into subs. Currently if I pull up a sub using MLs then they will move from their last position as the intensity comes up, causing a smear!

I think I saw some time back a method to setup a sub so that pressing a bump button would preset the focus on the MLs used in the sub. Then a couple of seconds later one could raise the sub to bring up the intensity with the MLs on target. Fact or Fiction?

If fiction, how is the best way to preset those MLs before lighting them up please?   

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