Yeah, I have a couple of modified air/coil '04 Z150SL forks with what's referred to a QR20 Plus. It's a toolless setup that works very well IMHO. I think part of the problem many have had with this setup is an improper installation order which can cause overtorquing of the flap retaining bolts or allowing the flaps to come loose and fall down.
In reality the QR20 in any of its forms is totally reliable, and it's a shame that bad installation methods have probably caused its demise. Anyway, I looked in my '04 manual, and apparently all the 20mm forks except the Monster, 888, and Shiver used the QR thru axle with a QR handle. The only difference was the flap retaining method...one with breakover flap and the other with an actual bolt to retain the flap.
If you obtained a thru axle for a Marz QR20 fork system that has a bolt-on end rather than a QR lever end, then I don't know why it wouldn't work. On the other hand, I don't know why you'd want to change from the QR lever end thru axle, as it's definitely been proven reliable. The flap and flap retaining system is where the controvery has been. Regardless Marz does make the bolt-on flap system to replace the tensioned flap system like yours. It's a simple setup and should work fine. I'd check with Marz and request the NON QR20 Plus bolt-on flap retaining system that uses a 6mm allen to install and remove the bolt holding the axle flap on each side.
I also just noticed that Marz does mention in their text that there is a threaded axle style like you have pictured, so you should be able to get everything from Marz. The simple bolt-on flap system I see pictured in the '04 manual looks like 4 total pieces...two pieces for each side.
Can you tell us why you want to change? Do you have broken QR20 Plus hardware? Are your flaps coming open when you ride? Have you had problems with the QR20 axle? Just curious. When our group goes on bike trips to Moab and such, I really like my QR20 Plus setup. I turn the bike upside down, pull the wheel off in seconds without tools, and throw the bike on a Hurricane Fork Up, and I'm through. BTW if you get a Fork Up for a QR20 Marz fork, don't worry about spending the extra money on the one recommended for QR20 forks...it's the same 20mm Fork Up as the standard model, but it comes with a QR20 axle...just use the one that's on your QR20 fork.
