how to deal with volume license that allows portable device install?

Hi there,

So we have a volume license for, let's say, 10 installation.
According to the license agreement, if a person uses a desktop and a laptop (not at the same time) he/she allowed to have the software installed on both device.
So in theory, if all 10 people have both desktop and laptop for traveling, we will have 20 installation in total.

What would be the best way to record this in software licenses page?
should I create a volume license for each individual (allow for 2 installation)?
or just create just one volume license that allows 20 installation?

If I choose to create just one volume license, it will be a bit hard to track who using what and where.
(The dual-install only allowed for the same user)

Thank you for everyone's advice :)