it would seem to me that an upgrade to r32 afm's would be a good thing. on an r32, one 80mm afm was sufficient for reading airflow for six cylinders. on an rb26 that was upgraded with r32 80mm afm's, each afm is only measuring airflow theoretically for three cylinders. depending on how full on the rb26 is, i don't think you would ever max out the r32 afm's.
thats just my thoughts on how it might work.