That's looking very nice Anthony!
Bunnings do cut but locally none of the guys bar one I spoke to the other day understand kerf thickness, 3mm for the saw blade. I wondered for years when every job was 3mm short till I picked up on the guy reading the tape measure equally right to left and left to right. His answer was "none of the tradies complain" and I explained it wasn't their own project and what's 3mm to them or the customer but went on to explain at well over $100 for a single sheet of 12mm marine grade play I wanted it cut accurately, not 3mm short (which it was).
https://www.thehandymansdaughter.com/saw-kerf/
I guess I studied fabrication engineering along with a lot of other subjects (too much time on my hands on disability pension) and my teacher would have failed me if I failed to allow for the kerf when cutting and welding materials.
What sort of bog are you using?
Are you going to tape it first with the fibreglass tape (self adhesive) like what is used to join gyprock?
It holds the filler in much better and isn't overly expensive.
