It’s down to personal preference I think. Both apps are a cut above any of the Lemmy only apps.
But I didn’t like Reddit Sync, so the Lemmy version was still a no for me.
Boost is Boost. It feels like home, and doesn’t cost an asinine amount of money to support.
Semicolons are optional in JavaScript unless you are combining multiple statements on a single line, which is generally not something you should be doing anyway.
I avoid them whenever possible. It encourages people to write poorly formatted code. But then I’m a python dev so I tend to be opinionated when it comes to whitespace.