How do I zoom in with canvas objects?

I'm using christina's 'Planometric to Isometric' technique as outlined in https://www.scirra.com/forum/can-we-stretch-a-layer-isometric-3d-engine_t129932

and I'm struggling to trim the excess window space or zoom in, I think I just don't understand the canvas object well enough yet to know how to do it within this structure.

Christina's Example:

https://dl.dropboxusercontent.com/u/28087823/Construct%20Examples/isometric%20from%20planometric/pacman2.capx

(uses canvas plugin)

Which builds as:

But I'm trying to get to a result like this:

One way can see doing it is bringing in a third canvas for the zoom, but that feels excessively heavy when we already have 2 going(not to mention that would break all the art in fuzzies or jaggies).

To be clear, I'm using Christina's file because I'm already doing more to canvas positioning to have it follow my character etc. So that one is just a cleaner example.

But I still need an oversized space to make it work.

the canvas can be any size, can't it? would it help if you set the final viewport size to the desired dimension and only resize the canvas?

You should be able to use LayerScale or LayoutScale to zoom in.

Something like:

https://drive.google.com/open?id=0B-xiq ... 0xDel9TRHM