Another thing that new
Disneyland runners should be aware of especially compared to WDW is that the sweep can work very differently out west, especially for the 5K.
Disney can and will shorten the 5K course in order to get runners out of the parks well in advance of opening. This past January during the 5K, there was a long line for Mickey and Minnie in their superhero shirts by Carthay Circle Theatre. The cast members were warning anyone getting in line that if we stayed in line, we might not be able to make the Groot line over by Mission Breakout as well. They also warned us that Disney might cut the course if we stayed in line.
I later on heard runners complaining how upset they were that runDisney cut the course as they missed running through Avengers Campus and Carsland.
So, it's important to remember that DCA opens no later than 9:00am and the last of the 5K runners are finishing after 6:30. As with all runDisney events, remember that a sweep or course shortening can happen not because of weather, but rather because of the logistics of clearing the parks before they open when that applies. So if a particular aspect of the course is important to run through, listen to warnings and be prepared to choose what you value more, that rare photo or running through a certain area of the park(s).
As always, my "warning" to new runDisney runners is that character stops are part of your mile time. So if you ran mile 2 in 10 minutes, but spent 30 minutes in line for photos, you really ran that mile in 40 minutes. Which can place you at risk of being swept. They will warn you where the balloon ladies. During one race, I was in DCA and they told us the balloon ladies were in Galaxy's Edge. This was to help us decide if the 30 minute line for Chip and Dale was "worth it." Slower runners may not be able to stop for every photo. They may have to choose which one matters most.
As a guideline, I recommend that if you're going to the parks after the race, then you may want to focus on "rare" characters during the races with the caveat that sometimes, the fab 5 can be in rare costumes during the race. Case in point, Chip and Dale were in their race costumes for the Halloween 5K last year and normal Halloween costumes in the parks. Mickey and Minnie were together in their Halloween costumes during the 5K.