Need advice on Tex-Mex salsa technique (water-in-pan method, char depth, missing flavor) HELP

I’ve been experimenting with salsa but mine always come out “good, not amazing.” I feel like I’m missing depth of flavor. I found a method that sounds interesting and plan to try it tomorrow, but I’d love advice from people who know Tex-Mex salsas.

The idea is:
• Pan roast tomatoes, onion, garlic, and peppers in a little oil.
• Add about ½ cup water to the pan and slide it under my gas oven broiler. The tops char while the water collects flavor from the vegetables and the pan.
• Blend everything (including the liquid) with dried chiles, spices, and cilantro.

Here’s the recipe I’m working with (about 2 cups yield):

Ingredients
• 2 lbs Roma tomatoes (8–10)
• ½ medium white onion (wedges)
• 3–4 garlic cloves (unpeeled)
• 2–3 serranos (or 1–2 jalapeños)
• 2 tbsp neutral oil
• ½ cup water
• 2–3 dried chiles de árbol
• 1 dried guajillo chile
• ½ tsp cumin
• ½ tsp Mexican oregano
• ½ tsp black pepper
• ½ cup fresh cilantro
• Salt to taste

Questions I’m trying to figure out:
• How far should I char the tomatoes and peppers under a gas broiler — fully blackened skins, or just blistered?
• Does the water-in-pan trick actually add depth, or does it just steam the tomatoes?
• My salsa ends up a little oily from the pan roast — is that normal in Tex-Mex salsas, or should I cut back?
• If I’m missing “depth,” is it more likely my technique, the choice of dried chiles, or something else?
• Does this method sound Tex-Mex to you, or am I mixing styles?

Any advice on nailing the technique (especially char depth and flavor balance) would be really helpful. I attached a pic of before I changed the recipe a bit. But that is the char I am working with.