Will I now be able to use separately purchased model packs without having to plug my Studio GX into the computer?
No, you can only do this if your purchase a POD Farm 2.5 license.
Yeah, that's how it comes across to many. But the sharing of a purchased license with the advent of the License Manager is an improvement (IMHO) on the previous method, and probably came about due to feature requests by many users.
Your triple pack is actually tied to your account, not the GX, but you do need POD Farm to run it, which your current version IS tied your GX.
When the interfaces were the "Red-Faced" tone ports, they came with Gearbox free with no plug-in. Then when Gearbox plug-in came out (which was quite pricy at the time) , it was a paid upgrade. Then when POD Farm came out, it was a paid upgrade. Then POD Farm 2 came out, it was also a paid upgrade. So basically the POD Studio interfaces, you are getting POD Farm 2.5 for free with the trade off that the GX is your dongle.
It's sorta like if you by a computer with Windows 7 already installed, it is tied to that computer, versus buying a copy of Windows 7 that you can install on any computer.
The advantage purchasing the POD Farm 2.5 Standalone, it will run run with virtually any ASIO USB audio interface.
So should your GX get stolen, lost are damaged, you are not forced to use a Line6 interface and you still have your purchased model packs.
POD Farm 2.5 stanard is $99 USD.