As a non TM user , but with a great interest in innovations and challenging the norm , there are a few requirements I would need to make me want to get a TM . ( I have dabbled in the past , and do not currently have the work in to justify one) .
I would get one on the principle of ,,build it and they- customers , will come.
I thin most off the shelf TMs are way too expensive for what they are and they have changed little from when they first came out, I guess there is not the $$$$ for R and D .
A few years ago I saw Micks early home made TM , I dont remember the details , but it was impressive.
I would want .
1, A water cooled engine , preferably diesel , or lpg powered , for the reliabilty and in the case of petrol , quietness, also red diesel or lpg for lower operating costs.
2, A blower configured so that a waste tank is not needed , in the style of a prowler.
Potentially , no tanks at all would then be needed so long as a water source was on site.
3, Portability some components such as pumps ,and hot box and control panel could be neatly boxed/fitted in the van allowing it to be used for other purposes once the engine/blower was lifted out, and/or there would be space to fit other equipment in the van , or a smaller van could be used.
4, The modular idea which Mick uses , making maintenance simple.