Since @beefnoguy was asking, we decided to squeeze in a return trip to Noodle Boy to try out this Hong Kong style Zha Jiang Mian, which is different from the usual Noodles with Soybean Paste versions from Taiwan and Northern China.
Noodle Boy

Zha Jiang Mian (Shredded Pork with Special Sauce) - HK Style:
@beefnoguy you’ll have to guide us through the authenticity of this, please.
It had a very sweet and slightly tangy flavor, with a little bit of heat. We brought along a friend from Taipei and she asked the waitress who confirmed that this version had Ketchup(!)
but with some “additional sauces.”
It definitely has a bit of that Hong Kong Egg & Tomato Over Rice, with a touch of “Sweet & Sour” vibe to it. The Marinated Pork Strips tasted fresh and meaty, and generally it was this sweet-tart-tangy flavor with Egg Noodles.
I’m not sure if we liked it or not. It wasn’t bad, but it was totally different from what we’d expect to eat with Egg Noodles (we’re so used to Wonton Noodles, or those Egg Noodles deep fried in an HK Chow Mein, both very savory). 
They also gave us a bowl of the Wonton Soup with this order:
@beefnoguy are we supposed to drink this on the side? Is it to be enjoyed like a Wonton Lo Mein?
We couldn’t leave without trying their most famous dish of course:
Wonton Noodle Soup:
This was light, not overly salty, a nice savory broth with meaty, massive Shrimp bursts of flavor from their Housemade Shrimp Wontons.
Delicious!
And I remembered to try @Sgee’s recommended method! 
A dollop of their Chili Sauce with a few drops of their Red Vinegar. This was so good! Thanks @Sgee.
It lent a tart, spicy kick to the lightly briny, meaty, savory Housemade Wontons, and the Egg Noodles.
I can’t imagine measuring exactly 2 - 3 drops of Red Vinegar every time, but the flavors were great and our friend from Taipei was laughing at how serious I was in trying @Sgee’s method (being super careful). 
Overall, Noodle Boy still delivered some wonderful Wonton Noodle Soup with great Housemade Shrimp Wontons. The new Hong Kong-style Zha Jiang Mian was fun to try once. I think if we grew up this, we might have more of an affinity for it, but maybe it’ll improve over time if we try it some more. 
Noodle Boy
8518 E Valley Blvd, Suite #B108
Rosemead, CA 91770
Tel: (626) 280-8963