Just had a look at Roamless with a view to getting set up for a trip coming, and noticed they have a "New"
business option which I am investigating. Seems to simply be multiple people all sharing the one set of credit. Looks to be great for multiple people (possibly a couple) and mulitple devices, hopefully avoiding the need for separate blocks of credit and multiple orphaned amounts. Looks like what I need for low daily usage across a couple of people and possibly multiple devices, across multiple countries but with uncertain data use for any one person or device.
Only way to set up seems to be via a contact form, so I have sent that off and see what happens.