The majority of straight users tend to strop right before the shave, in fact most strop while the first layer of lather is on the face to make sure that it has time to work on the whiskers....
Some of us actually strop again before the second pass, again while the lather is working on the whiskers...
All this of course is personal preference, but you asked

Stropping after the shave is mostly used to make sure the edge is clean and dry, again a personal thing....
The belief still remains that the edge needs to rest overnight then be re-aligned right before the shave...