[Bug]: Scara kinematics ignoring M669 R parameter in RRF 3.5.2

[droftarts]

See forum thread https://forum.duet3d.com/topic/36516/scara-manual-control

User: However, there is an issue with the R value. I even increased it to R500, but it exceeds this value and continues until it reaches the limit defined by the distal angle, which is 150(endstop). If it continues to be commanded in that direction, it moves in the opposite direction and stops at the -151 distal angle.
It seems to me that the situation starts with it ignoring the value set in R.
droftarts: If you command it to go into any area within the 900mm diameter central area, I would think it should stop at the point it gets within 450mm of X0 Y0. If it continues to attempt to get there, I think that sounds like a bug. Can you confirm that's what you see?
User: No.Only stop when reach the 150 distal angle(420mm of X0 Y0 approximate).
droftarts: I think that's the default. From 'Serial SCARA' tab of M669 https://docs.duet3d.com/en/User_manual/Reference/Gcodes#m669-set-kinematics-type-and-kinematics-parameters
Rnnn (optional, RRF 2.03 and later only) Minimum permitted printing radius from the proximal axis. If not specified, it will be calculated to be slightly larger than the distance between nozzle and proximal axis when the distal axis is homed.
So it does look like R is being ignored.