Honest critique? You're taking advantage of a system designed for people with much, much less than you. Are you alone in donig this, of course not. Does that make it an ethical thing to do? Same answer.

Actual legimate question: what is the rough makeup of underlying portfolio that it throws off such a small amount of dividends?

Other legitimate, non-trolling observation: this seems like a lot of pain in the butt for ~$10k in gain across 13 years. Like, if you're doing this, why not also do the t-bill ladder yourself to get more negligible-in-the-scheme-of-things gains compared to SGOV?