Minsc is mentioned, although doesn't feature as an actual character, in Baldur's Gate: Descent into Avernus
As you noted, Minsc is mentioned in passing in the D&D Encounters module Murder in Baldur's Gate (written for 3.5e, 4e, and the "D&D Next" 5e playtest), specifically that there is a statue of him and Boo in the The Wide, the great marketplace in the Upper City. This detail is featured again in BG:DiA, where it is explained that what had been presumed to be a statue was, in fact, actually the petrified characters themselves - and at some point in the years between MiBG and BG:DiA they were cured and set to wandering the world again:
Statue of Minsc and Boo. For years the Wide hosted one of the city’s most cherished landmarks: the Beloved Ranger, a statue of a powerful warrior in plate mail wearing a cheerful grin and cradling a hamster in his hands. Recently, though, the statue was revealed to be the Rashemi hero, Minsc, and his “miniature giant space hamster” companion, Boo, trapped under the effects of petrifying magic. When the magic was dispelled, it freed the heroes to walk the world once more but robbed the Wide of a bit of its charm. The merchants complained loudly, and a replacement statue of Minsc and Boo was promptly commissioned and set atop the pedestal where the actual heroes stood for years.
However, he does not otherwise feature in the adventure. It seems likely that this specific detail is a way of keeping the character available for use in future 5e material - establishing that Minsc & Boo have been petrified for the last hundred or so years neatly avoids the issue that a normal human like Minsc who was active in the late 1300s DR should have been dead (or at best extremely old) by the 1480s and 90s, when 5e's FR material is set. (As a miniature giant space hamster, we can probably assume that Boo's lifespan isn't an issue.)
He's also seen as an easter egg in an illustration in Waterdeep: Dragon Heist
The section of W:DH's introduction describing The Yawning Portal tavern includes a cartoon illustration of the tavern's layout full of depictions of famous characters of D&D and Realms lore enjoying the tavern's attractions. Minsc and Boo are number 22, located between Volothamp "Volo" Geddarm and Krydle (a character who features alongside Minsc & Boo in the IDW D&D comics).
Of course, this depiction doesn't imply anything canonical about Minsc & Boo's activities or whereabouts.
Minsc and Boo feature in WotC's The Descent livestream event
If you widen the net a little, Minsc doesn't feature in any other officially published written material, but his character did appear in Wizards of the Coast's 2019 live play livestream event The Descent, in which he is found trapped in Avernus with a motley collection of other heroes and eventually manages to escape back to Baldur's Gate (though the canonicity of this adventure may be questionable).
Here he was played by Jim Zub, who had previously written the character in the IDW D&D comics. Boo was played by Matt Mercer, of Critical Role.