Ann: 2018 AGM Presentation, page-25

OK, I think some people need to do some research.

If you can produce on 200mm, you can produce on 300mm. Its just the size of the wafer, the processes are exactly the same. Leti have 300mm inhouse and can do it anytime, but you dont need it for work up at this stage, since you can estimate yield and test for working chips and 200mm will get you enough chips for the task at hand, which is to field them out to potential partners and researchers and to do your own testing.

Why produce 400 chips when 250 will do for each iteration at hand at this point? 200mm gets them what they need now more cheaply and with less wastage and its probably easier to get access to the 200mm fab.
The produced chips are the same.

What people seem to miss is the acknowledgment that:
"Findings show that our working cells will fit on much smaller geometries (smaller than 28nm)"

28nm is the market sweet spot and Leti have shown costs go up at smaller levels from there at present BUT if the cells can go smaller due to good tolerances without significant extra engineering effort to do so (mask shrink) then this is a competitively good thing. For some designs, getting below a certain size may require significant new engineeering of the core design to cope for small tolerances.