Made a few tweaks that perfected the dish to my family's liking. First, double the ricotta mixture. It's hardly enough and you want this to be a really enjoyable dish.
Second, use shredded mozzarella instead of slices, the slices end up getting tough to cut through with a fork after cooking and kind of ruin the enjoyment/ease of eating.
For the tomato sauce, I added a 1/2 tsp of red pepper flakes, about 2 tablespoons of balsamic vinegar, used 3 tbsp honey, way more seasonings (at least a tsp more than what's listed) & salt. Including a tsp of fennel seed instead of 1/2.
To me, the amount of seasoning being asked for just isn't enough to come through in flavor at all. Slowly taste test after adjusting and chances are you won't under/overdo it.
I also use Italian turkey sausage but that's just my family's preference.
We eat this two days in a row, and I make it about once a month. It takes a while but is very worth it.
I know people don't like when you suggest a whole bunch of tweaks to a recipe. And to that I would say this recipe is a very good "skeleton" to which you can build off and change to your liking.