I guess if that works for you, then it works, but it shouldn't be necessary. I use central position trimmer mode, and trim it with a click, just like I would with a UH-1. You don't have to hold the trim down to temporarily disable the autopilot on the Mi-8 because use of the trim isn't "programming" the autopilot in the same way as it is with Ka-50. The Flight Engineers knobs are what accomplishes that.
For about a month now, following the practices of a more experienced pilot, I started flying the Ka-50 with Flight Director ON. For me, this makes the Ka-50 fly more like the Mi-8, specifically in that I don't have to hold the trimmer down while manuevering. The only catch is that when I want to autohover, I click FD mode Off right before hitting the Autohover button, since if the FD is On, you wouldn't be able to Autoturn to target or stuff like that. And then of course, I turn FD back on again when I want to move on. As with anything, Your Mileage May Vary.