This! Given the premiss that you still use YouTube and not invidious or piped, there's no need to have another app on your cellphone (unless you really like it, and enjoy the app customization that revanced allows to for instance).
Mull + uBlock Origin+ SponsorBlock + script in uBlock to hide Shorts, I feel you don't need anything else :)
Hmm I seen weird haha but how about the list of posts / submissions?
On the comments I get that it's not necessary for now due to your explanation, but I feel that implementing an automatic load or something on the list of posts would be usefully.
First of all, great job, this is now my new way to browse Lemmy on Desktop :)
I would like to make some suggestions for you to consider:
Infinite scrolling, instead of pagination
On Sidebar, present the instance / community mods (like in the OG lemmy frontend), being these ones clickable to go directly to their profile (useful to send messages to mods)
On Sidebar, have the same markdown as Lemmy OG on the instance / community text / description (bold, italic, etc), since today everything has the same formatting and it's harder to read
I understood your case, so I don't know if this will helps anyhow, but I just wanted to suggest https://lemmyverse.net/communities as well.
Really great site to search for communities and instances, with available filtering.