Dean;
Just a comment from a northern neighbour of yours. These are just thoughts, and the only arguing about them I'll do is in person over a pint of beer. 
My Tich was built in inch measurements, but when moving about NZ and Europe, most everything was metric, as was a lathe I picked up while living in NL.
I converted, it was tough at the first, but became really easy.
Now, I convert inch plans to metric before machining, even if I'm doing CNC, as, for me, metric is just so much easier.
I'm surprised how Model Engineer has adopted metric, it's no where near 100%, but it was about 0% a decade or two ago.
Building metric in an inch country; most all of my materials now come in inch form, but a 1/2" round bar of brass I use as 12.7mm, etc, etc.
I can remember trying to buy a BA tap when living in NL, and I have the same issue back here. Metric is pretty universal; yes there are some thread pitch differences in older country-specific metric tables, but it is really as close to a world standard.
Kids know metric. In the USA, most of the fasteners on 3D printers are metric, as are the spools of filament. Cars are metric, etc, etc.
I'd love a little CNC Sherline lathe, but the one major item for me is that the fasteners are NOT metric, so it means yet another bunch of taps/dies/spare screws; like the Whitworth and BA screws on two of my British made machine tools, it is a hassle I don't want.
What you choose to do is TOTALLY up to you, and the inch (english, imperial, whatever you wish to call it) system works very well, but the world seems to be adopting metric, so your re-drawing to metric may prove to be more popular in the future, and maybe the "defacto" go-to for accurate LBSC drawings.
(BTW, should anyone complain, right now we have a partial solar eclipse going on, so, rather than fire back vitrol, just shake your head at the poor Canadian, and blame the "Eclipse Madness"
