Ticket conversion question

[jerseyduke]

I have an 8 day trip coming in Sept. Someone MAY be coming. And it may be for the whole Trip, it may be a part(first half or last half).
I am going to add them to my room reservation.
Now for the FP+ issue. (they do not have an AP)
My plan is to buy a ticket for the entire length of the stay. Worst case some of the days get wasted, but its not enough money for me to concern myself with.
If I buy it to start 9/14 and they dont start it to 9/18, is that an issue?

Next question is, if the person does not go (this wont be known for a month after FP+ window opens), is there an issue altering the ticket to be used in December - which would be for the same person - or if not, just unassigning it, and converting it to my AP renewal when the time comes(next spring)?

I have not done this since this flex date ticketing whatever you call it started

 

[BillPA]

Not a problem if they don't use the ticket for several days. BUT if you switch it to December, you will have to pay any increase in ticket cost for that time frame. If it's lower, I don't think Disney ever gives any refunds.

 

[jerseyduke]

Not a problem if they don't use the ticket for several days. BUT if you switch it to December, you will have to pay any increase in ticket cost for that time frame. If it's lower, I don't think Disney ever gives any refunds.

Thanks. I would not be concerned with any refund if there even was one. If it was a significant amount of money (which I doubt anyway), I could just roll that ticket toward my AP renewal and but a new ticket for december as I see it