I have a basic RTW question; please forgive me since I'm not quite sure how to phrase the question other than give a specific example.

I have a C RTW STAR1 ticket booked routing roughly as:
SFO UA X/NYC LH X/FRA LH MUC

LH BCN

LH X/FRA LH TYO

UA (back to SFO)

which has 3 stopovers over at least ten days of travel, and not visiting a city twice.

I need to be in Munich for the night that I arrive (a Wednesday) and need to be there for a real stopover Fri-Sunday before moving on to Barcelona.

Can I add a day-trip from Munich out to Lyon to meet with a colleague on Thursday? Specifically I would therefore do:
SFO-JFK - FRA - MUC (overnight < 24 hours on Wednesday night) - LYS (spend 8 hours to meet a colleague) - MUC and stay in Munich for several days.

Is this a legal routing? Presumably the the first transit in Munich is a normal transit and the trip to LYS is also considered a long transit prior however it seems odd that I would need to transit in my stopover city (Munich Wednesday nigth) prior to my actual stopover in Munich.

Anyway, so curious whether this is legal or not, and if there's any jargon that would describe what I'm trying to do. (Other than "crazy".)

Thanks much.