i just tripped over this thread snooping around while i sip my caffeine: i don’t know if this is still relevant, or even if it would be helpful for you, but when i want to add pizzazz without materially changing the nutritional profile i get a TON of mileage out of premade seasoning blends! and they’re great because they’re zero extra work, just shake the bottle and go. maybe they would work for your situation if you still have these constraints?
here are some of my favorites:
everything bagel: i mix this into egg bites or scrambles, shake it onto cottage cheese, and use it to season meats. a lot of companies make a version of this, they’re all about the same, i happen to have einstein bros right now. it has more substance than some of the others so you might want to check fiber etc since it has some sesame seeds etc.
trader joes 21 seasoning salute: this makes things taste like thanksgiving without all the heaviness! i mix into grain/salad dressings, and use it to season meats. if you shake it on toast, it’s sort of like stuffing!
elotes: many brands make seasoning that imitates the flavor of mexican street corn. jazzes up everything from vegetables to meats!
penzeys spice blends: penzeys has a wide array of options!!! many are also low salt or salt free. i really like revolution, outrage, buttermilk ranch, sunny paris, fox point, tsardust dreams, and singapore curry for savory, and their pie spice or cake spice blends are great dessert-leaning choices. so many ways to use all of their options, and they often have really good sales going at penzeys.com - many of these would work in a variety of spreads or dips.
do you have an NO2 canister, like for making whipped cream? you can use that (or the old-fashioned way with a whisk or beaters) to aerate things like yogurt, to make it more like a mousse or dessert. penzeys baking blends in something like this can be close to decadent! and personally i have a sensitivity to cocoa that causes a rash, so no chocolate for me, but i bet it would work great if you aren’t allergic!