I am having a problem on my Framework 16 where if my three finger click is spread too much or too little, it registers as a left-click instead of a middle click. I frequently get the separation wrong, which is frustrating. I never had this problem on several generations of MBP.
Is there a way to configure the touchpad to make middle clicks register more reliably?
Hmm… I don’t have a problem with the finger spread being too much or too little. For me, a mis-registered middle click (3 fingers) is when not all of my fingers are registered as I tap or click (I have tap to click enabled).
No matter how wide or close I tap or physically click with my 3 fingers, it registers the middle click AS LONG as I make sure all three of my fingers hit the pad at the same time. Being slightly off is what makes my 3 finger tap/click register as either a 2 finger or 1 finger tap/click (2 finger - right click, 1 finger - left click).
Are you sure your issue is because of not having all 3 fingers registered simultaneously vs the spread?
I’ve tried putting my fingers down one by one, and then clicking. That actually makes the middle click more reliable, not less.
I found this similar question on the Framework 13, but the question there is also unresolved.
Weird, because I did the same and tried different spread sizes and it’s consistant for me.
I’m sorry I cannot validate your issue. 
But glad I don’t have the issue. Sorry that doesn’t help you though.