I haven't used a portable install but used to. I used them for a couple years for my main library. Here are some issues and notes I had. It was a long time ago so there is a good chance things are different and fixed.
Artist images won't show up, in a portable install, if the cover art folder is located on the same drive as said portable install
I think I solved this with a separate partition. It may no longer be an issue.
When i want to update my portable install i first update my regular install then do a portable installation into my existing portable install folder to update it.
Remember your regular install and portable install have to be the same version.
Note that every time you copy a portable install you have to re-licence it.
This can be done by re-installing MC on top of your existing portable install from a PC with an activated copy of MC.
I think I may have had issues with ASIO DAC using ASIO but WASAPI and direct sound worked fine.
On a fresh install of MC there are no lav filters (used with ROHQ) and not all audio encoders are there either.
This only matters if you plan on using the portable install somewhere without internet.
To get the filters start a video with ROHQ enabled to get MC to download them. You will also have to do this when a new build includes a new version of lav filters.
To get audio encoders you can convert an audio file to each format you want to get MC to download them.
I believe around half of the available encoders are included in a fresh install of MC.
There is more stuff that gets downloaded these days. It is best to play a video with Red October, then ROHQ, then the new JRVR, and also a bluray with menus if you want to get everything.
Issues with portable installs:
When backing up a library from a portable install, import/zone settings are not included. So when restoring a library from a portable install, all import/zone settings will be default.
But...If you restore a regular install’s library to a portable install, import setting are there. If you then backup this library it will contain import settings, but only those from the regular install. Changes done during portable use will not be there.
When backing up a library from a portable install, import settings are not included. So when restoring a library from a portable install, all import settings will be default.
But.
If you restore a regular install’s library to a portable install, import setting are there. If you then backup this library it will contain import settings but only those from the regular install. Changes done during portable use will not be there.
This does not matter if you don't use "Tag on Import"
You can use a portable install instead of a regular.
When you want to do an update, copy the portable install to a drive and update it somewhere where you do have internet.
After your update, and while still on the internet, play a couple videos so MC will download everything needed.
Copy the portable install back to your home PC.
I was using a portable install for my main library which I do not think they are intended for. I had no internet so it was the only way to use MC other than packing a desktop to a coffee shop. Now I have bad and limited internet. I just connect my PC to the internet when updating MC or ripping a disc. Life is easier this way.