Is the GMail account associated with your main Mail profile?
If so, it might confuse X1 if you add it as a separate IMAP account. Results might show up twice.
If you do want to add it separately then you might want to tell X1 to exclude that area of the PST. Then again, maybe you have the GMail account feeding into the same folder structure that you use for other accounts. In which case, you could also end up with duplicated entries.
I'd go for the simplest operation. Or one designed to meet your search needs.
If so, it might confuse X1 if you add it as a separate IMAP account. Results might show up twice.
If you do want to add it separately then you might want to tell X1 to exclude that area of the PST. Then again, maybe you have the GMail account feeding into the same folder structure that you use for other accounts. In which case, you could also end up with duplicated entries.
I'd go for the simplest operation. Or one designed to meet your search needs.