I'm not sure if I'm cargo-culting here or just trying to figure out the point of Chesterton's fence, but I would be worried about the effects of significant amounts of salt in sourdough starter. Salt could theoretically inhibit yeast growth less (or more) than bacteria, potentially causing the ratio to move in an unhealthy, less flavorful, more sour, or less voluminous direction. If it works and tastes good though, this is a super clever and awesome idea.
Lactobacilli are among the most salt tolerant of common bacteria. In fact, when making wild ferments, the salt is what selects for them (if you make low salt wild ferments, they're less sour and have off flavors). Yeast do alright in high salinity, but they need oxygen to thrive.
Salt-containing starters will taste fine and be healthy as the short chain fatty acids produced by the lactobacilli are what give most of the flavor and health benefits. Your rise might be a little bit weak though. The best thing you can do is take it out frequently and fold it a few times to oxygenate the dough.
