Is any one familiar with how to remove the permission to enter a Custom Address on a Sales Order/Invoice?

this is driven by the Customer records, if user role have at least Edit permission then they can add custom address. To remove this option just make the customer record VIEW only for the role, so they wont be able to add new "shipaddress".

Hi Sam-I-Am. I thought as much and changed the permission level to Create but they can still Create a Custom Address on the Sales Order Form. I just tried the same with the Permission level set to view and Im still able to make this change in the Security Role

to stop from entering any new address permission needs to be View for customer record. Otherwise you can use a workflow to restrict adding new address

Yeah, that would be my solution. If you can't train the user to not enter a custom address, I would use SuiteFlow to restrict adding the address all together. Might be able to use a Client Script to remove that custom option, but not 100% sure.