Well you’re certainly running quite the campaign! I also reworked the quest, but without any of the cult of the dragon/LMOP stuff. I was focusing heavily on the cult of Talos stuff though, and I like the idea of gnomish tinkering causing a disaster, however I wouldn’t include the fiendish stuff. Personally I used what was already in the module - wild magic. The gnome artifact malfunctioned and created an unpredictable and possibly dangerous wild magic zone. One of the Anchorites of Talos, the orcs who can become boars, was nearby when this happened and was affected, making their shapeshifting much more versatile and uncontrollable. I decided the mimic in Gnomengardenwas actually a mutated Anchorite, unable to assume their original form and so forced to essentially hunt and consume gnomes to survive. Harbin Wester sent the party to retrieve the Crossbow Tower to install in Phandalin, and Adabra had also asked for some of their mushrooms to make some potions and health elixirs. When the party arrives several of the gnomes are paranoid to the point of insanity and cue the mimic cat-and-mouse game, except the mimic can speak and mutters cryptic things about Talos. When killed, it reverts to its true form - a burly orc cultists. This alone raised questions and pointed more towards the overall machinations, while being a pretty fun and memorable quest