Well, I'm certainly not going to skip Lassen at this point, and I'm not worried about the travel times/distances. It's more a matter of dividing my time.
I had originally been thinking of doing a quick tour through Lassen, hiking out to Bumpass Hell, and making a quick stop at Burney Falls, as part of a long day on the road to Ashland. However, while all of the roads in the park are open, the Bumpass Hell trail is not yet open, so that might not be possible. There are a few other trails that look interesting, but many of the features that I think I'd want to see aren't right off the main road, so that may force me to spend more time there.
I might trim my time at Crater Lake down to a half day, but I'm not sure yet. I might just play it by ear and decide while I'm actually on the road.