I did not see blkRandom function.

I have added the function in the Addendum.

New to R, though would like to use blockrand and/or simstudy to generate a permuted block randomization (stratified by sex) for a cross-over RCT. Is there a way to repeat ID #s, such that it recognizes a participant needs to be assigned to both active and control conditions? Thank you for any help!

I assume that you are randomizing the order of the intervention arms. If that is the case, you could define two arms A and B, where A would be control/treatment and B would be treatment/control. If you take this approach, you can use blockrand directly.

Yes, that is correct! Very much appreciate your input.