Reset panels every 5 years. 0.6 arcsec offset. 2 arcsec absolute. Difficult but doable. Not major cost driver.
Solar spec seem to be within reach, using machined grooves.
Recommend to focus on production plan. The US MAC favored 345 because it is in the range of optimum frequency for dust emission and it provides a reasonable intermediate step between 115 and 650 GHz. Circular polarization requirement. Specifications and Goals. Suitable arrangements should be made to include imput from representatives of Japan and Chile.