copy-and -paste fails

I do a lot of opera reorchestrations ( ie very big files , many instruments, many changes of instruments) . Since the loss of the "album" function. I have relied on making segments of the score < 500 measures (after which note entering really slows dow) and then copy-and- pasting to empy measures appended to the first segment, only copying and pasting sections where there are no key signatureor time signature changes. It is laborious but mostly works. There are a few places that fail: tempo marking (eg "a tempo") almost never transfer, rehearsal numbers mostly never transfre and instrument changes ( eg horn in F to horn in Eb or oboe to English Horn) never transfer.

Is there a way to either append a score to another score intact or another way to copy-and-paste everything that is in the copied measures not just the notes?

Thanks