You have a good point there. Consider once cycle of the process you mentioned
Let's say you make a master, make a plaster slip mold, Make a green piece bisque it, maybe glaze it (another unknown),
Fire piece ......it's off by 6mm here and 8mm here.
Even carried out by an expert there is a great deal of essentially irreducible time: waiting for things to dry adequately;
waiting for the next bisque/glaze firing; etc. Achieving all this in the 3 weeks Imaan mentions seems a tall order -- even
ignoring the repeat cycles needed and the delays inherent in a learning process.
Maybe a dependency chart with all the dead-periods included is in order.
Your suggestion of 3D ceramic printing for a prototype seems a potentially viable alternative, although presumably the
stoneware appearance may well be lost. Quite a lot of learning-experience on the lead-times of ceramic processes to
include in a project write-up thought (if that gets credits). Assumes availability of: a suitable 3D modelling service;
suitable solid modelling software, and the ability to get up to speed on it quickly. I presume that a 3D modelling service
would have an accurate knowledge of shrinkage rates.
Just brainstorming. If you had to produce something in a time-frame that permitted one - but only one - cycle, and had the
necessary skills, maybe you might stand a chance on the wheel. Throw many cups at slightly different scales, say 100% to
120-ish% of the desired final size (trimming against templates). Put them all through the two firings. Pick the best sized one.
Ugly, but if you need just one prototype ASAP ...