rocket spear - is it worth maxing?

There aren’t many detailed guides on the optimal level for the Rocket Spear. Some recommend keeping it at level 9 for the 8 spears. However, what I’m curious about is which buildings the Rocket Spear can one-shot, similar to how the Fireball works. Here’s what I’ve observed so far (my RC is level 37):

Level 24 Rocket Spear

Cannot one-shot TH15 Air Defense

Level 25 Rocket Spear

Can one-shot TH15 Air Defense Cannot one-shot TH16 Air Defense Cannot one-shot level 21 Archer Tower Two-shots level 3 Spell Tower 4 spears for lv3 Monolith

Level 27 Rocket Spear

Still cannot one-shot TH16 Air Defense

Credits to Itzu for the screenshot of the maxed Rocket Spear stats. I know the video is old, but the stats remain unchanged except for the buff adding 2 extra spears.

I hope players with maxed Rocket Spears can share their insights on what defenses it can one-shot.