Has anyone figured out how to "dumb down" the bots while still "signed-in" (albeit offline) to GameCenter?

Here's the deal...  These days, I race with two goals in mind... 1) to have fun; and 2) to gather useful information for this site.  For the second goal, I need to dumb down the bots so I don't have to waste time rerunning events in order to finish first.  But I also want to capture my total and fastest lap times for inclusion in the leaderboards that will (eventually) be a feature of MRR.club and I know that screenshots showing "Guest" will not be acceptable.

I *think* I did it (somehow) before in my 1.1.2 version, but I can't seem to do it in 1.5.  I tried finishing last in an elimination event at least a dozen times, but the app keeps recycling the same *real* players as my opponents.  I don't have any friends on the GC account I use for 1.5 - so that's not an issue.  I'm just wondering if I simply need to finish last *many* more times to get down to the FM "players", or what?