Doubling On Clarinet And Bass Clarinet

Question for any clarinetists: I'm writing a second clarinet part that's mostly bass clarinet, but now and then it steps back up into the higher range (Concert Eb3-Ab4, which, of course, would put it in Bb clarinet territory). If you were playing the part, would you rather I:

A. Write the higher section for Bb clarinet, so you could briefly switch up to the higher instrument, or:

B. Just leave the whole part on the Bass Clarinet for the higher notes? (Inquiry - How much louder is the bass clarinet than the regular clarinet in this range? Would I need to write it down a dynamic?)

I've never been able to figure out which instrument bass clarinetsts prefer to play - bass or Bb. I've also wondered how hard it is to switch between them during performance. For instance, after getting used to blowing all that air, does it risk squeaking when you shift back to the Bb?

I've doubled Bass and regular before. It's not an issue, as long as you give them about 30 seconds or so to switch. If it's mostly bass clarinet, then you should probably keep it as bass...but at the range you are talking about, maybe it should be regular. However, high bass clarinet is a unique sound, and it's not really louder than normal clarinet. I say if you only have it for a few bars, then don't, but for a more extended passage, keep it as what you wrote.

Thanks. Sounds like a plan.