Portability with Thunderbird Portable

I saw quite a few posts on a search that hovered around what I'm doing, but I'd like to describe my setup so as to get a little feedback. I considered posting this over at Mozilla, but given that my Portable Thunderbird is at the center of things, I came here. Mods, just holler if you prefer something different.

I run Portable Thunderbird on an external drive, doing most of my work from work on a Win32 system. Works great, and at home, when I'm on a Win32 system, it's just more of the same. All my mail is on the external drive, which I back up on a regular basis.

On my main system, I also spend a lot of time inside Ubuntu (multi-booting). Rather than play around with WINE, where I observed some quirks with a few of my extensions, I simply installed the Linux version of Thunderbird, configured the software with the extensions I use with my Portable Thunderbird installation, and redid my accounts by hand (which was no big deal, as I didn't really want to fool around with profile migration and so forth). I point each account towards their corresponding mail folders on my external drive, and after a few days, everything seems to be OK. No lost mail, no kooky behaviour.

I also have a Mac, and am planning on installing Thunderbird there, too, and doing the same thing I just described with my Ubuntu installation. So....is what I'm doing, with shared mail folders across multiple installations of Thunderbird, kosher? Anybody else doing something similar, and if so, any pitfalls of which I should be aware, or any tips/tricks? Thanks in advance.