Yes. At any time you can change your Swan Bitcoin savings plan. You can change the amount pulled, the bank account information, and whether you want your plan to be daily, weekly, or monthly. To do so to your Dashboard, then click "Edit Plan" as shown below.
Then you will be taken to the plan setup screen as shown below. Here you can change the amount and/or frequency of your plan.
On the following page, you can confirm your banking information or add a new bank account.
Finally, on the last page, you will get a confirmation screen to confirm all of the change changes to your recurring plan.
For information on how that will affect your fees click here.