Marching Ants: Change strength of visibility / Or alternative selection

The purpose isn't to mask, it's to move, skew, rotate the selection, and the machine ants influence the visibility of the changes being made.  I might be misunderstanding you solution, here's a quick example of very fast sketch, which need quick alterations.  As you can understand, hiding the marching ants also hides the transform controls.

The point of this is that it's extremely quick to do while sketching.

You can simulate variable marching ants in a Quick Mask channel by using the Trace Contour filter preview. You wouldn't want to commit the filter, of course, just preview it.

Just a suggestion in the meantime (we all have our working habits): you can switch to Quick Mask mode, where you can adjust opacity and color of the mask to whatever you like.

The marching ants have a very big limitation: it doesn't show how much selected, only that it's more than 50%.

FWIW, I mostly treat the marching ants as a confirmation that there is an active selection. For any precision work, I normally work directly in a layer mask, even sometimes adding a temporary adjustment layer just so I can work on the mask. When finished, the mask can be moved to where you need it - or it can be turned into a selection if that's what you need.

As the story goes, there was a fierce discussion right at the beginning with the first release of Photoshop: should they make the marching ants or the quick mask the default way to show selections? The marching ants won, but not by much.