Cost plus doesn’t make things go faster. The only thing that makes contracts go faster is an award for early delivery, and you can do that with any procurement vehicle. Cost-plus is for when you don’t know what you need. Fixed cost is for when you do. Fixed cost is going to kill you in change fees if you’re wrong, cost-plus will kill you in a bunch of other fees. All tools are useful.
Artemis 3 is good but Artemis IV needs block 1b and probably BOLE. Both have elements of new development.