<R21> was recently updated to add M2.5 x 8mm screws (as used in the low-profile high-strength shaft collars). However, it does not explicitly mention spacers or washers for the HS shafts, with an approximate inner diameter of 5/16".
Q&A 2091 approved the use of M5 spacers, though not mentioned in <R21>, provided they add no functionality. Does the same apply to spacers and washers for the HS shafts? (These could be fabricated from approved parts, so there doesn't appear to be any added functionality.)
Thank you.