If I had to suggest something:

• Quick switching between accounts on different instances (a couple of clicks, instead of another website in another tab)
• More configurable UI. Quickly switch between seeing/not seeing read posts, NSFW, NSFW blur
• Combined communities list and/or wall between all your accounts, so that you see more

Cool! What do you want to add to it to distinguish itself from the browser version?

Why are you selecting for long names? 😅

In terms of an optimal load spread, it’s best if the lemmiverse is split into multiple equally sized instances. If you use an instance just for yourself, it doesn’t actually decrease the load on the main servers in any way. The only thing you get is a guarantee that your instance won’t suddenly go down.