Unsurprisingly, it’s a pretty easy way to restore a near 1:1 experience. Some reddit specific things won’t carry over for obvious reasons, but current theme, media handling settings, etc. can be imported from the Reddit app.
To get there, open the left sidebar, select Settings > Advanced > Backup. On the Reddit side, you’ll select Export and save your settings file locally. On the Lemmy side, select Import and navigate to and select the file you exported from Boost for Reddit. Once done, you’ll really be right back at home.
I did that, but now I don’t have the view parent button when bringing the comment bar.