Blue board and acrylic render or paint

I have a total of about 10m2 of new wall to clad, and I'd like a flat finish (ie not boards).

Blue board with paint or an acylic render seems to be the logical way, but I'm very open to alternatives.

I'm a bit confused about to do joins in the blue board. There seem to be a few different products available, some with multipart applications (base coat, top coat, hardener) and some that appear to be a single application.

Given the relatively small area I'm doing, I'd prefer not to buy several large buckets of stuff and use a fraction of each.

One of the products mentioned to me was acratex - has anybody got experience with this product? Can I get joins with this or a similar product smooth enough to paint, or should I use one of the textured acrylic finishes (Hadrian was one product I saw)?

Does blue board have recessed edges like plasterboard, or does jointing tape just on top?

Any advise gratefully received...

Can't help with the coating but as far as the blue board goes yes it has a rebate along 3 edges.