My first scope was an ETX-90EC. Meade makes a micro-focuser that fits tightly along the back of the barrel so that it can still achieve zenith. This focuser was controlled by the autostar and has the part #1244. It appears that JMI also makes one though I have no experience with it.
The problem you might have though is when trying to find focus, the image will shift, so the auto-focus routine may not work.
12" pier with HDX110 using EQMod
ASI 1600 mono/color mains with ASI290MM in off-axis
ASI filter wheel
Moonlite focusers for the sharpening
AT115EDT w/.8x for the light
Fedora Linux, 100% INDI