Today I tested my homemade Topre stem in the Synth, and I'm sad to report that the design of the synth won't permit the Topre switch housing. The cap gets close to clicking down, but the inside walls of the key are just a little too thick to let the housing in all the way. I can definitely modify the synth base to allow for the housing to fit, but I had hoped I wouldn't have to.
I know this tool wasn't necessarily designed to produce Topre, but a boy can dream.
Just a heads up to those people that had the same idea that I did.
The synth itself works great for it's intended purpose. It's a wonderful sculpting platform, and a great way for beginners to produce clean MX keys without having to do the work to make a custom underside. I had some initial quality control concerns about my particular synth, but they've been addressed and I don't have anything negative to say about the process.
I can't wait to see future improvements and designs of this tool.