I definitely suggest you make a linkage! They are simple and relatively easy to make.
You only need to make sure that the distances between pivot points are consistent (the actual distances don’t matter all that much, as long as they don’t get in the way)
This post has some basic ideas to build from: Throwing my hat in the sled modification ring - #222 by pillageTHENburn (note: this post was very early on in the design phase of the linkages, literally just days after I came up with it, they have come a long way since then and there are hundreds of them in use today - they work great)
The two designs on that link that have been made and tested with good results in the real world are the “3-bar top mount” and the “3-bar 45˚”. The top mount idea clears bigger routers easier but the vertical bars need to have a special shape to avoid hitting the chains. Also since half of the non-vertical bars are under tension and half are under compression any error in your joints will compound and result in a lower-than-calculated router bit. This doesn’t necessarily mean it will be problematic though, especially if you are very careful with construction. dlang has been known to make these as a kit if you want to just buy them. The ones he sells are metal and of nice construction.
The other well tested version is the 3-bar 45˚, this linkage design is very solid and since all non-vertical bars are under tension any error in the joints will only result in a bigger distance between your chains and the router bit, the good news is this can be measured and “goes away” when you calibrate (rotational radius). They are both 3 bars and have the same number of pivot points etc. Both can be easily made with a drill press, some wood or metal, some clamps, and some care! If you want a quick solution I am currently shipping the laser cut wooden linkage kits (3-bar 45˚) (I have 25 going to the post office tonight!). I have them in stock and ship same day (heck, even tonight if you place your order soon 
). linkage link
If you have any questions about linkages please let me know, I’d love to help!
-Logan