No, please don't do this. Those lines were put there for a reason and removal is supposed to be opt-in, not opt-out. I am opposed to this on principle.

Those changes look good to me! Good work here. I think you're making a good choice to just leave the IM dependency fixed at 7. Do give it some build testing to make sure that CMAKE_BOOL is behaving the way you want it to.

Ah, I missed that.

If you wanted OPTIONS_SINGLE, it would look like this:

It seems to me that most meta-ports should not be direct dependencies. Why not generalize this? DEPEND_ALTERNATIVE= USES=python:xy with a specific version

It installs the package in 4 seconds. This is all I ever wanted in this world.

In D18833#402213, @tcberner wrote:

Rename to CMAKE_DISABLE_FIND_ON/OFF

I don't feel the greatest about the opt_CMAKE_DISABLE name. It implies that it disables a feature, similar to opt_CONFIGURE_ENABLE. Can it be named something that's more specific to what it does? opt_CMAKE_DISABLE_DEP, opt_CMAKE_DISABLE_PACKAGE something like that?

"Created by" lines should never be removed without the express consent of the person named in there. Please, put them all back.

LGTM