I went ahead an purchased my ticket MIA-MUC via LHR (was able to clear my SWU). For the BUD-MIA via LHR (they had to waitlist me, ugh). This is return is 11 months away.
The LHR-MUC and BUD-LHR is operated by BA. The MIA legs are on AA.

But my question is I will overnight (21 hours) on the return. Should I assume that my luggage will be tagged all the way through to MIA since that is how it is ticketed, but should I assume I will still need to collect it because they aren't going to hold it overnight? Would I even WANT them to hold it overnight - is LHR safe? (I wouldn't do that in MIA EVER). I easily could put my PJs & next day wear and such in my carry on.

Anyone experience this type of overnight connection heading to the U.S.
Thanks