This site (jiten.moe) looks like something I was looking for, thanks!
Given BunPro can already work with csv and anki decks, that’s probably the fastest way to go.
Regarding the manual import, I guess it’s still something to automate, but the difference with JPDB is you get file export right away, so you don’t need to parse pages, just download the files and combine those it a way to fit header, subheader and then up to 500 items per file.
Thank you for the recommendation, @EdBunpro!