I've worked on a bespoke science experiment not too dissimilar to JWST (though much cheaper). These types of machines never resemble anything like mass produce

I've worked on a bespoke science experiment not too dissimilar to JWST (though much cheaper). These types of machines never resemble anything like mass produced parts. All of the tooling is custom made for one shot. The next machine will be the same story. What we take forward to the next machine are the lessons learned and technology developed.