Hi Roberto,
Yes I think its technically possible but not trivial. I implemented the newest data layer (Firbird) in about 3-4 weeks of full time effort.
The biggest problem is how it will be maintained over time as changes are made in mojoPortal. I have no wish to maintain a data layer for Access even if someone else does an initial implementation. So if someone wants to implement it and commit to maintaining it over time they have my support and encouragement but I will not maintain it myself as I laready maintain the other data layers.
When I right click the web folder in the release files and check properties I see the folder is about 93-94MB of files not counting the size of the db. Some files could be weeded out to make it smaller but myself I would not go with such cheap hosting that I have to worry about it. It probably won't work well on that kind of cheap hosting anyway.
Access is a desktop database not really designed for lots of simultaneous users. Its not a good platform for professional web applications in my opinion.
Best,
Joe