anon703820,
If you turn off editing permission for the books you wish to ignore and set the range in the wordlist tool, the wordlist will show you only the instances in the books you want and when you correct a word, you will only be asked to correct the words in the books you have permission for. I have not checked out project plan assignment behavior in this regard but I would hope it would behave the same.
I think there may still be a slight problem with the spell-checker considering outside range instances and not clean when capitalization, for example, is incorrect in an out of range book. It hasn’t happened to me clearly enough for a report yet.
Shegnada