WLP630 in 10 Gals. - Starter, or Underpitch?

I'm planning to do a 10 gallon extract batch of Berliner-style kinderweisse this weekend. The plan is to bottle it in a few weeks, and let it age in the bottles until next summer. I ordered ingredients, including a vial of WLP630, and delivery is scheduled for today. My plan was to do a 1 liter starter and split it between the two 5-gallon fermenters. This morning's research indicates that doing a starter with a lacto blend isn't a good idea. Oops - should've done the research earlier. But I don't need to order anything else, and I'm not paying shipping for just another vial of yeast. So, I've got a decision to make:

1) Eff it and do the starter anyway, hoping that the long aging process will let the lacto thrive and do its thing despite the starter. I was hoping to use this opportunity to play with the new stir plate I got at the beginning of the year. I recently became a father, and haven't had a chance to play with it yet. This seems like the worst of my options, though.

2) Split the vial between the two fermenters with no starter, hoping that due to the low gravity (target 1.031) the yeast and lacto will be able to chew through the wort despite being underpitched. I really want to go ahead and do 10 gallons - maybe this will work? Again, I recently became a father, so brew days are looking to be few and far between for a while. Getting 10 gallons out of one day would be great.

3) Play it safe and just do five gallons, saving the extra DME and hops for another day. If it's worth doing, it's worth doing right. Right?

I really want to go with option 2. What are your thoughts?

Okay, let me boil it down (pun intended) to a simple question: what do you think about splitting a single vial of WLP630 between two 5-gallon batches of 1.031 kinderweisse?

In the end, I decided to just do a single five-gallon-plus batch. Boiled 5.5 gallons of water, killed the heat, added 4 lbs of wheat DME, returned to boil, and added an ounce of 3.9%AA Hallertau hops for 10 minutes. Chilled to ~70F, drained to fermenting bucket and pitched the WLP630, which I'd let warm up to room temp. It's bubbling away now, and I think I caught a small whiff of sulfur, although that could be wishful thinking. Easiest brew day I've ever had. Worst case scenario, I'll just have a weak hefe. We'll see what happens..

ALSO...

My first legal home brew here in sweet home Alabama.