Would there be any benefit to feeding a sourdough starter with beer instead of or in addition to water?
Actually, there is an answer in the question that I linked, which speaks to your question. However, now that I've read the question again, you are technically correct that it is not a duplicate. I'll also add that the folks here seem to think beer in your starter is not very beneficial, but I have found nothing definitive. Perhaps you could create two starters, one with water and one with beer, then bake two identical loaves and report your results as an answer here.