So, I decided to see what can be done with this using a focal reducer. Nothing special, it is an 'unbranded' 0.5x focal reducer, I think it cost me about £15 when I bought it, so, lets get this straight i'm not talking cutting edge optical quality here. The simple rule with a reducer is the further the lens is from the chip of the camera the greater it reduces the image scale. However there is a caveat, the more this reducing factor the greater the spherical aberration and the greater the field curvature; basically things go down hill.
With today being the third day in a row where i've had some sun to play with I decided to do me some experiments, nothing too scientific, but you get a flavour: The shots are over 2 days of the same active region. Now I know there will be some 'movement' between the 2 spots, but essentially the distance between them is constant enough to give us a comparison.
All shots here with the ED80 (f7.5) and the DMK31.
First off native resolution with the quark on the scope to give an efl about 2600mm. Way too much! (IMHO)

Yuck! Soft, flat and lacking in contrast.
Next up, the '0.5x' reducer on a short (15mm) nosepiece...

I still think the image needs a bit to be desired. Measuring the distance between the 2 spots tells me i'm getting a reduction factor somewhere around 0.7x.
So to todays part of the experiment. I stuck an extension on the short nosepiece and the reducer on this, to get me up to around 23mm from the face of the camera. Here are the results:

This image is starting to look a bit more like the standard I like...
However, look closely, there is a focal shift across the image from left to right. It later materialises this is because the 'extension' piece I used (half of a variable polarising filter without the filter in - the half that 'rotates') does not sit square at all, infact there is slightly more than 1mm shift in 'height' from one side of the cell to another. If I get day 4 on the sun I have already found a more appropriate and 'square' extension section. Measuring the distance between the 2 spots indicates the magnification factor I have here is 0.5x. I tried a few more shots:

Notice top right struggling with focus - the quark is very sensitive to focus with its telecentric output beam, it is either in focus or it is not, so a tilted focal reducer will not be ideal at all! Next up a bit of 'mid disk'.

You'll notice that right side out of focus again, but the keen eyed will notice the corners are darker, so, maybe a bit of vignetting coming in?
Either way, running at 0.5x means the efl is about 1300mm with my setup, which is pretty close to the nyquist ideal of about 1100mm based on my setup. With a bit of tweaking and perseverance this may well just work...