I have a very simple flat door sill plate, that I was going to vacuum bag mould.

I suspect the detail of the lettering may be too much for the weave to handle as there are several changes in direction in very small areas which are bigger than the actual warp or weft of a 200g so it is unlikely to follow nicely.

You could cut each letter individually out of ProFinish so that the face of each letter lies flat against the mould surface and looks perfect; then lay a piece of conventional carbon across the back to fill in the gaps. Alternatively, what about a different process and use a product like GlassCast to effectively clear cast the lettering and detail - the added benefit being that you will then have a flat face against which to lay the carbon.