@acbilson forget what I said...
As they stand now without framework - #WebComponents are a nightmare to do in #vanillaJS. Let my last three weeks of back and forth be a testament to that!
(눈_눈)
Tried to attach #ShadowDOM to this blasted table, and it won't let me. Turns out we can have it on only so much base elements, and the most generic ones at that: div, article, section, etc.
To top it all, unhelpful #JavaScript error messages made me go debugging for other 3 hours!