Don’t know if this quite qualifies as a build but I was tired of having no place to land the toolholders near my machine. Since the rear part of the machine is outside of the cut envelope, I opted to just toss some scrap plywood on the back.
One thing I’ve learned in the process of switching to an ATC is that you’ll never have the right collet when you need it and you’ll wind up cannibalizing perfectly setup toolholders to swap to a different tool.
You and I think different… When I had my ATC I had 10 tools and 10 holders. I never had a tool holder out of the rack… I guess I did that because I was sick of buying expensive ISO30 tool holders 
Looks like you need to drill more holes. Right now, you can only rationalize 5 more toolholders.
Are there lower-budget toolholder and collet options for the S30C for roughing bits, where maybe you don’t need quite as much accuracy (or maybe you do, I’m just not knowledgeable in this area)?
10 more iso30’s and 6 more 1/4" collets are on order I’ll need to make a second toolholder board!
There are, yes – amazon has some iso30 toolholders of dubious vintage for as low as $20/holder. That’s over $100 less, per toolholder, than maritool (~$135 per holder, I think?). I splurge on the maritool collets ($20/collet) but I can’t quite justify $130 a toolholder.
I only cut wood so the idea of runout affecting my cuts is not a big deal. If I was cutting exotic alloys I’d be more concerned about tolerances but there’s no point in chasing thou’s when the wood will adjust to ambient humidity anyway.
