The dangers...

 Early start. Awake from 4am. Up just after 5am.

Started back on the Medium Rig earlier than I usually would. I don't feel drousy, just a bit dopey -- that is more dopey than usual. This mental fuzz resulted in a perceived weird issue.

1. I created a plate object for the command module, instead of disrupting the command module itself. This creates another object to track, but it means that you don't mess up the existing object.

2. But when I render the scene, the plate changes position. This mismatch between the viewport and the final render is really worrying. I've seen it before with things like terrains and scatters.

I checked the usual causes: mostly modifiers like displacement that aren't uniform between the viewport and the final render. I could not find the cause! This is Blender 5.3! Damn it! Buggy Blender 5.3!
<narrator: It wasn't a bug; it was a user error>

I'd created a copy of the command module without thinking and turned the original model off (but only in the viewport). I'd then moved the new version slightly before creating the plate object. So now, when I rendered the results, the copy of the module that was invisible in the viewport made it look like the new plate object was moving; it wasn't. Dong!

Things I learned today: Check the basics, especially for object copies that are not uniformly enabled in the viewport.

I am setting a deadline of Sunday evening to complete the build. I must get back to terrain work for Raptor next week.

Did I mention Blender 5.3?

A day later than expected, the Blender 5.3 release candidate dropped, sporting a new splash screen. 

So far, so good. I imported my 5.3 settings and haven't encountered any real issues. I expect many addons will get updates over the next couple of weeks as changes to core technologies, such as node 

behaviour or underlying Python code, require them.

Progress

More details!