If you mean Boogiemon, he has nothing to do with Tamers!Impmon. Boogiemon debuted a year after Impmon/Beelzemon, and he was most likely just created as a celebratory Digimon to represent the TCG card St-666.
As long as it has been used in any official capacity, any evolution is canon to the franchise. If you meant a specific part of the franchise, like Tamers or Frontier, then those evolutions are narrowed down and certain evolutions are "canon" to one part and not the other.
However, even within the same part of the franchise, canonicity can be further divided between different media like toys, games, animes, and mangas. A notable example is the controversial subjects of Plesiomon and Ophanimon within the Adventure part of the franchise. Certain Adventure toys and games use them, but the anime portion (specifically Tri) instead uses Vikemon and Holydramon. The same thing applies to Tamers!Impmon. In one of the Digivice toys, Meramon/SkullMeramon is the "canon" evolution; but in the anime, there is no "canon" evolution (yet) except Beelzemon himself.
At this point, I consider "canon" to be only relevant if you're talking about a specific series within the Digimon franchise. If you're talking about the entire franchise as a whole, "canon" is too general and irrelevant. What I consider relevant is the "intent", whether a Digimon was designed and created for a specific purpose (like an evolution).
Regardless of "canonicity", Baalmon is clearly "intended" to be an intermediary stage between Wizardmon and Beelzemon. He's literally a (surprisingly coherent) combination of the unique features of Wizardmon together with the features of Beelzemon (ironically, the features seem to be based on the original Beelzemon, not the Xros Wars one).
The main issue is that Wizardmon was not originally "intended" to be Impmon's Adult (though the franchise within the past several years seem to settle on Wizardmon as Impmon's most common Adult). This issue is shared with Ogremon and Digitamamon (While it feels more like a placeholder, Titamon's intended Perfect is still Digitamamon, and he is even given pink nails to show that intention).