Hifi amplifiers are often described as having defeatable tone controls, meaning the tone control circuits can be disabled/bypassed to avoid generating unwanted "electrical noise" in the output.
That link is to 124,000 hits on Google, as compared to none at all for disableable tone controls (or disablable tone controls, which strikes me as an even worse spelling for a highly "iffy" word).
As it's now emerged that OP wants a term suitable for use in the context of on-screen software controls, I should add that disableable is probably the most suitable word anyway, since we commonly speak of disabling features in software.
But you still probably wouldn't speak of toggling the disableability of a disableable control, since unless you've got a very convoluted user interface, the control still has the attribute "capable of being toggled between enabled/disabled", regardless of whether it's currently enabled or not.