following requirements below (no heat exchanger)

58mm standart basket "Portafilter Size"
Flowmeter for volumetric dose
Brew boiler min. 0.5 Liter / max 1,5 liter
if dual boiler.: steam boiler min 1.4 Liter / max 3,5 liter



Is It's me there are blind or is there only the "La Marzocco GS3 AV", "Rocket R9" or "Kees Vander Westen Speedster " on the market?

Then we have Portuguese Fiamma Vela if the basket is 58mm? (but no thanks anyway) https://www.fiamma.pt/machines/vela-pp/

I find the new "Carimali GENIUS Pro" nice machine, but filter basket is only 57mm (edit correction: Carimali use 58mm)

Machine like EMC Elektronika will be nice if is its was a Dual Boiler or even bezzera Matrix line if the steam boiler was biggere

Why is volumetric dosing a must-have feature for you? It's convenient, but not as consistent as weighing your liquid output and manually stopping the brew.

Because I have a manual dual boiler for many years and will like to have my hands free, even you have volumetric dosing machine you still can brew manual

Dual boiler is not at must, but heat exchanger machine is not a option

Is 58mm essential because you already have 58mm baskets and portafilters, or some other reason ?

My machine is nominally 57mm (with a stack of different capacity baskets to fit it) but a 58mm tamper works fine.

In real life use with it, you cannot tell the 1mm difference.

You have a good pointe, but I also have 1mm can do a huge difference in what tamper, funnels, distributor tools, filter basket, i like to use Pullman and VST basket, with 58,5mm tamper, I can not limit my self to buy a machine out off the standart 58mm, so thats why 58mm is so important.

If the "Carimali GENIUS Pro" was with 58mm, its will be perfect, but unfortunately its only 57mm

I guess you're stuck with the narrow choice of the ones you've found in that case.

What's your probllem with those ?

8000 US$ and R9 is to much computer profile electronic (dont like and trust in High humidity area) , incredible market is so narrow

...

Breville dual boiler?

I think the bezzera is what you want, and honestly I wouldn't worry about the size of the steam boiler. The matrix or the duo without the e61; the models with the bezzera group head and electronic dosing, would fit the bill. And the steam? With the pid controlling the boiler I would bet it'll crank just fine. 1200w element in a 1 liter boiler will crank steam.

No way small steam boiler, have you ever try? 1 litter is to small even a NS Oscar performs better
if I cant get my taget, I will stay on my manual PID e61 Dual boiler
I cant belive La Marzocco GS3 AV and Speedster is the only choice in this marked right now if we dont go to the commercial line