There should be no necessity to move anything into a templateVM. Never do that.
You can git clone and build the software in a dispvm, qvm-copy the compiled binary or package to your appVM and install it to /usr/local/bin/ inside your appVM. You can also consider to use bind-dirs inside your appVM.
I don’t know how this sdk tool works and if it’s possible to make it use proxy (or if proxy is supported by it at all).
It seems that sdkman install script is installing all files in user home directory so you can just install it in an app qube instead of a template. No need to use bind-dirs in this case.
It’s installing a new version of java so I can compile something. If I install it in the AppVM and compile in there, I’ll not have it in the template, which is what I want.
I really want to connect the template to the Internet.