I'd ask the other devs.  To me in every language bools take two values - true and false.  It's bothered me a bit we are sloppy with true/false enums like that and I can see a good argument for sticking with FALSE/TRUE for ones that are treated like bools.

The other argument for this is the smartsave code is already really complicated and confusing so it would suck to propagate another set of parameters mapping true/false to arbitrary strings through the whole configuration.