A universal starter?
I would like to ask about your experience with converting a sourdough starter. At the beginning my second starter was 60% hydration (75% white, 25% whole rye) but as it produced a very liquid dough  I followed the advice of some TFL members and converted it to 2 pure starters - medium rye 80% hydration and white 60% hydration. The problems has been solved but I do not like feeding 2 different starters.
Therefore I would like to ask for advice what would be the best universal starter that I can always convert according a recipe?
I mostly bake at least 50% whole wheat with some rye (10-30%). But I also often prepare a rye sponge and in future aim to try 75-100% rye. On the other hand, from time to time (even if not very often) I make something sweet (eg Sourdough Challah). As the temperatures now are quite high (86F / 30C), I do put the starter into the fridge.
The yeast and bacteria certainly are influenced by the regular feeding so I wonder whether a 100% white mother starter converted into rye in 2 feedings would produce a good rye. Or, on the contrary, whether a rye mother starter would not give a strange tang to sweet sourdough recipes.
Thank for help!