Meh, why hard-coding all the paths in a portable release. Paradox and not customizable
Have a look at Diashapes Portable (not supported anymore, works with Dia 0.97 only) and Dia Portable. User could set custom install paths, settingsdirectory, appdirectory ... and with the proper ini-entries it just works. Always.
Oh, and there is a major bug:
(line 95) {IfNot} ${FileExists} `$EXEDIR\FirefoxPortable.ini`
is always true, so the default FirefoxPortable.ini will be copied every time and overwrites a custom one. No chance to define AdditionalParameters, LocalHomepage or something else.
Ah, so it is. I'll fix the bug with losing the FFP.ini in a followup release shortly.
There's nothing paradoxical about it only working with the default FFP install. This isn't designed for folks that want to put things all over the place on their drive. If someone wants to do that, they can easily copy and paste FFP.exe files wherever they want and reconfigure them to their heart's content. This is designed for folks who want it to just work and not manually tweak.
Sometimes, the impossible can become possible, if you're awesome!
not all folks want to put things all over the place on their drive, but many choose their install directory. Say you install Firefox Portable to \PortableApps\Firefox, then this little change from the default breaks FirefoxPortable 2nd Profile. And choosing the install directory isn't big tweaking IMHO, it's just normal behaviour.
Right, but someone who does that is a tweaker since, by doing that, they've already broken the ability for the platform to use FFP and the ability to easily do upgrades (they're going to have to manually select the install path EVERY single time).
In terms of second profile, you'd then need to go muck about with an INI file to get it working right by default anyway. So, you're just as capable of doing that with a FFP.exe and an INI at that point rather than an INI for 2nd profile. You're still gonna need to learn an INI and manually configure it.
So, again, no real reason to add the functionality here when it already exists for someone that wants to manually do stuff themselves.
Sometimes, the impossible can become possible, if you're awesome!