Many people (myself included) are disappointed by the Sniffer and feel that it is wasted potential. Sticking with the theme of "reviving extinct organisms" presented by the Sniffer, Torchflower, and Pitcher Plant, I suggest that these plants (and ideally more that would be added) be used to craft *new, otherwise unobtainable* dyes; it would be "bringing the dyes back from extinction" so to speak. Dyes are not required to progress through the game, nor is a large amount of gameplay locked behind the dyeing system. New and rare dyes would be worth the trouble of getting a Sniffer, but would not hinder the gameplay of those who don't care for the Sniffer or dyeing items.
There's also worldbuilding potential to point players in the direction of the Sniffer. For example: the player explores a desert temple and finds a "Fuchsia Banner" or something. They see in the sandstone walls carvings of a fuchsia colored flower and a Sniffer. The player then connects the dots "this special banner color came from that plant, and that weird creature has something to do with it."
Suggestions for new dyes:
-bioluminescent dyes ("glow" in the dark like glow squids) which allows for "glowing" banners, shields, and beds (maybe even wool blocks themselves)
-gradients
-bright colors like neon
-shifting textures (like the "sparkles" on sculk)