This is not a practical proposition on my 1973 Nauticat NC33 Mk1 ZARZUELA as mizzen mast boom is just above the aft cabin roof and hatch.
However I do have a long lead extension to my original NECO Autohelm which enables me to adjust heading as far away as sitting on the deck forward of the main mast. Better than nothing on a sunny day or when single handed.
I had a NC33 Mk1 Nautillia, with Capillano dual hydraulic steering and had no problem with the mizzen mast as it’s either fixed on the neutral position or if sailing with mizzen then you steer from the windward side, and DUCK when tacking!! It makes berthing easier from that higher position, and easier to shout at your crew.