Hello Simon,
Welcome to the Forum.
I have never seen an Alphie converted into an office.
Based on my experience with my rear conversion it is, imho, entirely possible to create a fantastic office for one, two at a push.
I have two bench seats and a small table, which would suffice as an office.
For a more capacious office permanent, or semi-permanent, middle or rear seat removal is a real option.
Some of the older vehicles have middle seating that can be rotated.
Do you need to be able to stand ?
You need to consider how to power any office 'equipment' though.
You have set my mind buzzing