wifey99999999, I hope you check the first post of the FRA connection thread linked from my signature line.

Your flight from LAX can arrive in Z, B or even C. It could be quite a long walk to passport control/exit and lines at passport control could be considerable. There are two WorldShop outlets in FRA, so make sure you know which one you are picking up your case from.

When I bought a Rimowa case from MUC WorldShop, I completed the enquiry form on their website specifying the model I wanted and when I expected to pick it up (date, flight numbers, arrival and departure times) about a week before travel. The following day I received a user name and password for a WorldShop account and a separate email confirming that they had reserved a case I had requested.

Regarding security at US airports vs FRA, I have summarised my views in this post which I will not repeat here. There is priority security if you are flying in C or F or if you are *G, though priority security is not always quicker. There are also fast lanes for passengers connecting to flights departing in under 30 minutes but I'm not sure if they exist for non-connecting passengers.

If the flight from LAX arrives early as it did yesterday and today you will be fine but FRA is a large and complex airport. Swissaire obviously knows the airport well and has been lucky. If I were you I'd opt for 90 mins in MUC than 125 mins in FRA but the choice is yours. Good luck!