OK, hotel is booked and I've reg'd the 6-Max and the Main Event. I won't pre-reg for the PLO as I fully expect to be still playing the ME through into the Monday night and don't want the hassle of trying to offload a seat I can't un-reg from.
If by some unforeseen circumstance I am out of the ME in time to enter the PLO I will go down the Alternates List route (on the assumption it will sell out ahead of time). As stated in the OP, if I don't play the PLO that part of the stake will be returned to investors.
And some good news, as can be seen from the bolded link in my sig... I'm currently enjoying some 'Run Good'!!
Let's hope I don't use it all up before the end of August.