It's already the case. Even one step lower in the chain, ASML sells prototypes of their new photolitho chip makers to the big chip houses years before they dev

It's already the case. Even one step lower in the chain, ASML sells prototypes of their new photolitho chip makers to the big chip houses years before they develop them. The chip houses understand that the first releases will require ASML engineers to babysit the new tech, patching design issues as they become visible through use. That is a de facto joint venture.