Well an 86cc DiTech would be nice but in speaking with Malossi the European sales determine production and they do not have enough European Ditech sales to justify the production.
Since Malossi has been in business since 1930, It's safe to say they don't make what won't or cannot sell. We have definitely seen that with The Franco Morini engine. Early fear that the company would fail did come true but not until 4 years of European engine sales and another 3 years worth of leftovers shipped here. A different engine bore, stroke and cylinder bolt pattern doomed it from the beginning. They didn't stop there... The crank and transmission input shaft splines are also unique so we couldn't use Minarelli components.
The Piaggio engine has now been in the SR50 for 10 years but the Ditech sales are still weak in comparison. Personally I just love the sound of a 2 stroke twin or triple. My last 2 stroke big bike was a Kawasaki 750 H2 Mach IV that I purchased from a best friends older brother who was later killed in an auto accident so the family wanted to purchase it back which wasn't an issue. My best friend and I still rode together a lot. Tim rod the 750 Triple and I had purchased a new 1000 Z1R. That 750 (if you could keep the front wheel down) would stay right on my rear wheel for a quarter mile.
With 10 years of Piaggio parts being available including a lot of Ditech parts being removed and thrown away, why not a 140cc Ditech twin. A couple companies, Christofolini being one of them make (on demand) a twin conversion for the carbureted Piaggio case for a staggering $3500.00. I will bet their sales of that conversion could be counted on one hand and anyone with one would surely have it on YouTube which I cannot find even a hand full of owners.
It may not sound like it but a 140cc twin Ditech would actually be quite easy to produce. The most expensive item would be the center case and crankshaft. Neither of which for a 70cc setup would need to be near as robust as what is being made now. It's not hard to join 2 crankshafts together which is what the current providers are doing. A fair amount of time is involved in designing the center case which by design is mostly based on each half of the existing case.
As soon as I have my Piaggio case scans in hand I am going to put a center section together and show it to my local machine shop which has no problem doing one off work. For the crankshaft the best place to have that made would probably be a shop that already does crank repair and balancing. A 140cc twin won't break the bank and current performance variator and clutch components will hold up under normal use. The reason for the case scans are to produce an engine without the integrated transmission so a separate transmission or separate variator system can be used. Of course the integrated case being already available would be the cheapest option.