A portable installation is characterized by the fact that it does not leave any traces on the PC.
The entry in the context menu is a shell extension that is stored in the registry.
So, your idea collides with the principles of the portable installation.
I'm using the portable version, too. And I'm missing the context menu, too. Indeed, the version of Mp3tag is really portable and that's a good fact. It exists a lot of portable applications which are not conform with the specific standards. They leave entries in the user directory and/or registry. On the other side many well-known freeware applications (audio player, editors, image viewers and system utilities) offer the possibility to (un)install their own context menu entries while in portable mode. Maybe Mp3tag will follow in the near future.
Could you elaborate a little bit how you see the integration of MP3tag in the context menu without leaving any traces?
Also, how would you like to see the implementation of a context menu function that points to a program that is not available as you have installed it on an external, removable storage that might even change its drive letter?
If necessary, the ability to temporarily activate the context menu entries, e.g. via special dll and/or writing registry entries.
And when the work is finished, the ability to disable the context menu entries, e.g. by unregistering dll's and/or removing registry entries. Now the portable device can be removed without leaving any traces.
I know, writing registry entries would not meet the requirements of a portable application, but it would be temporary. I am not a programmer and therefore do not know all the possibilities that exist.
As opposed to other applications, Mp3tag does not provide a way to enable or disable the context menu entries while using it. It only knows setup/portable version with/without context menu support.
It would be nice if Mp3tag would offer these option. Mp3tag portable (by default with disabled context menu support) would remain "portable" according to strict guidelines. In the last instance, it would be the user's decision how to use it.
Finally: I would also use Mp3tag "portabel" on my hard drive. Program and settings files in one and the same folder. Small, simple, fast, no setup or other restrictions.