My 2 sats: It's great that you're already upgrading and expanding and whatnot, but I don't personally feel it's needed at least at this point. I'd prefer your time and money allocated to simply doing more episodes for now - the current equipment / video quality is top-notch already.
Technical upgrades can be 'nice to have' later down the road (like 4K video etc.), but in a channel's starting phase, especially after already being as polished as yours, I'd prefer producing more content first.