Yes, I've had races do similar things before.
Because it's set up as two separate races on RunSignUp, you'll have to keep them as two separate races in the timing software, at least until registration closes (which is probably right up until the race starts). After the race has started, or before you need to print results, you can then use the "Race Day Tools > Combine Events" feature in the software to merge everyone into a single set of results. Ideally they would get with RunSignUp (maybe after the race) to get everything combined into a single event if possible, but here are the steps that can be taken in ART:
Let's assume the race is called "Clueless Race Director 5K". Here is what I would do:
1. Create (or pull in / link) each race into the timing software if you haven't already.
2. I would name the alumni race "Clueless Race Director - Alumni" and name the other race simply "Clueless Race Director 5K". After combining events we'll be left with just the "Clueless Race Director 5K" that has both athlete types and all "divisions" that you'd need to print for both Alumni and Community awards.
3. Create an "Alumni" Athlete Type in the "Clueless Race Director - Alumni" race, and create a "Community" and "Alumni" athlete type in the normal "Clueless Race Director 5K" race.
4. Create all divisions (award breakdowns) you need, even for the 'alumni' divisions (might only need one) in the "Clueless Race Director 5K".
5. You can now do the Dynamic bib assignment, checking in, syncing or anything else like normal up until the race starts to pull everyone into the system up until the start of the race.
6. After start (or when registration closes - Now we're ready to combine events:
- You could pull in only the "Clueless Race Director 5K" to the Timing screen and just minimize it if you want, or start only the 'Clueless Race Director 5K' race and then close the timing screen. Either way, we need to get back to the Open Race screen so that you can click on "Race Day Tools > Combine Events". You'll select both events, and then finally select just the "Clueless Race Director 5K" to keep as your master event. Now click "Time Race" again and you should be good to go.
The most important part of this is to have all of the divisions and athlete types set up correctly so that after the merge you have everyone assigned to the correct 'athlete type', and you can easily print a report that breaks all of the award winners out exactly like they need.
If you'd like for me to remote in and look at things with you just let me know what day/time is best.