Was looking through the reference designs you have in github.
I figured the difference between nRF52840_qiaa_var1 (what is qiaa ?) and nRF52840_qiaa_var2 is the use of the DC/DC converter.
I cant find any difference between the rest and var2 .. all seem the same.
Maybe add a README file describing each plus considerations for/against using that particular reference design ?