I use alexandrite to switch between different lemmy instances and change the default post layout to card style. When I first started using lemmy, the I found the difference between the reddit and lemmy in the post feed to be jarring as I was used to a card style layout.
I find on a desktop browser, I prefer to be able to see images without opening a thread. I initially used kbin.social exclusively for this feature but disliked the way their sorting algorithms are setup. Having the ability to easily switch instances is also a nice feature particularly for new users who are unsure what lemmy instance they want to use.
A single caveat for lemmy.world users: Since lemmy.world is an ongoing conflict zone network load-wise, trying to log into your account every time the app switches accounts will often fail. Best keep your user account logged in through the default frontend at all times as backup.