I appreciate your interest in this feature because it does work well - especially for fast moving comets that have faint tails with fine detail in them. People who just guide on a star will use long exposures to catch the faint regions - but they will be blurred in each subexposure if you don't move along with the comet. High end mounts can self-guide and track comets and asteroids, but mid-range mounts need guiding, and you need a way to offset the motion from the guidestar. I think Maxim can only accept a sequence of x,y guidestar moves rather than the actual RA/Dec rate of motion of the comet, which MetaGuide can work with.
Here is an example using a c11 and a comet moving fast enough that 2-minute exposures leave the stars trailed, but with shift-guiding the comet is sharp: http://www.astrogeek.../Comet103P.html
I think some of the older QHY cameras now have video drivers that will work with MetaGuide - so you may be able to use it. But I think some can and some can't. If you really want to do this, MG will do it for you, but you may need a different guide camera.
Unfortunately unless you have a high end mount, you won't reliably be able just to pulse in dec. and have the mount respond as you want. RA may work ok - but dec. motion is much less reliable and you need to guide relative to a guidestar. In RA you also need very low periodic error if you aren't guiding. But if you can use MG, you just find a guidestar, enter the RA/Dec rate of motion of the comet, turn on guiding, enable shift-guiding - and the comet will be very accurately tracked since the mount is locked onto a nearby star and moving relative to it at the exact specified rate.