I’ve been making both those for years. Not with lily buds yet (I picked some up, just haven’t used them yet.)
Which mushrooms did you use? They add a lot of flavor — I use dried black mushrooms and assorted fresh mushrooms.
The kecap manis in the recipe tin eats version may be more intense than regular soy sauce, not sure if you used that or substituted.
I love the flavor of sesame oil to finish, though it’s not always in the original Hong Kong version (which gets most of its flavor from intense toppings, and some drizzled sauce at the end).