Opt you cast at your leisure and at the low cost of one mana it should barely ever be detrimental or even noticeable on your curve which is much more so the case with the slightly more potent sorcery alternatives that get in the way of things more
Dark Confidant has also been a long time Plan B for combo decks, whether in the sideboard or the maindeck, such as Paulo Vitor Dama Da Rosas Dark Depths deck from Pro Tour Austin: Creatures (11) Lands (24) Spells (25) Dark Confidant is great for finding combo pieces and great when you dont assemble the combo
The app recently launched its first competitive season and theres already plenty of interaction on the competitive leaderboard
Rakdoss Return Ive touched on this a few times, but the combination of a discard effect and pressure on your opponents life total is highly effective
Very likely playable in a spell-slinger deck (especially as you likely include the Adventure dragons in that deck), but otherwise a flat out 7/7 isn't worth it to jump through hoops for
Relying on having dorks in play makes it narrower, less good early and more situational