The holds are in increments of $100. So on the day of arrival Disney will put a $100 hold on your credit card on file. So if you don't want any complications just don't charge back to your room Folio account.
In your case it could only be a max of $300. Based on a single $100 hold per each resort check-in.
If you don't charge anything back to your room via MB or resort restaurant charges. On check out day Disney will put through the actual charge balance on your hotel Folio. This is were it gets a little more complex if you chose to make lots of charges to your hotel Folio.
Since Disney only adds holds in increments of $100 as you make additional charges to your resort Folio they almost never match the final balance that Disney actually processes on check-out day. That's what tends to slow the removal of the $100 holds.
The credit holds fall off based on your Financial institution processing rules. Some can drop in 24 hours and other providers may still show as pending 3-5 business days later.
So if you don't want to worry about Credit card holds use your Smartphone for mobile orders and for other store, restaurant or cart purchases use your Credit card or even a Gift card.
Note: If you want to use Gift cards the
MDE app does not store your Gift card number like it will for your Credit card but you can just put it in a note and copy and paste into the Mobile purchase transaction.
Dave
