If you want it creamier, add something fatty. Milk, butter, peanut butter, sesame paste. Not a lot. Just a dash. A small slice of butter. Different chili oils. Primarily the bits in the oil rather than much of the oil itself. Buy fried shallots. Baby bok choy makes it a little sweeter. A bit of napa cabbage adds some good flavor. Tubes of tomato paste freeze well, squeeze some in
Throw in something a bit acidic. Lime or vinegar. A fermented or picked vegetable. Kimchi, som pak, something. A little tamarind paste can add a kick to it. Frozen dumplings. Thai basil. Shichimi togarashi. Five spice. Curry powder.
Back to the peanut butter, I always have powdered peanut butter for low calorie peanut butter flavor. Try a dash of soy sauce or fish sauce into it. Cayenne and/paprika powder.
If you have whole spices on hand, it doesn’t take long for coriander seeds, fennel, star anise, cardamom, etc to add flavor to a broth.