The issue is that you will probably stuck with no payout for a week.
In a meanwhile they will simply pump-dump with your money.
What are you talking about? No payout for a week from where? Who will pump dump with your money?

You need to clarify what you are talking about.
Any new pool in general has no liquid assets. So its common practice for new Pool to disable payouts for first day-two.
In our situation we are talking about the Multipool having no 365c at all (not now not in perspective), so it needs to buy it.
In place of Multipool operator any person seeing the price is risen will play with Scrypt Alt (you mined) and wait for 365 price to stabilise.
Most probably they will try also to pump-dump on 365c to catch an exploding train.