Replaced another pro-mag follower with a follower from a ruger mag, and that also brought the pro-mag to full function. Good enough for plinking, but I suggest avoiding them for a duty pistol.
Assuming 6.8's question relates to the above comment, the ruger follower is not a smooth fit in the promag carcass. It tends to have a bit more friction at the top of the magwell. Probably bit of light filing on the sides of the folower would make it fit better. It has fed the last round, but once in a while the follower end up not-quite-flush. Just have not used the mag enough to think it will always be 100%.
But its still better than the original promag follower. That would either jam the last round or lock back without feeding the last round.