I applaud and thank anyone who contributes their hard work—whether it's a Lead's decision, patch or community feedback. That said, I've personally thought the ability to switch themes in the Customizer is a "hmm, okay" concept. An acre of real estate is being neglected in `wrap > theme-browser` via `themes.php` respectfully. There's a convenience factor jamming mucho into El Custo, but this orphans pre-existing screens/components which could better escalate on-boarding, e.g. capturing intent (switching themes) only via themes.php first, then contextually scale upon that acquisition inside Custo's guts. It can get a bit squishy & schizoid once you're inside Custo, so maintaining focus on 1 theme should be the only task. Just my silly opinion :) P.S. I also applaud people who can stomach long-winded Trac tickets ...my eyes go dry and brain implodes.