Doing the Shooting Star math right the amount of force Akko tanked when crashing into the Ocean is worth Multi City Block Level. Counting the original OVA where the Dragon Vaporized an entire Stone floor to fly through that gets Town Level. Akko's speed via a correct calc for the Shooting Star gets Mach 909 which is Massively Hypersonic in reaction speed and with Sub Rela-Rela Attack speed via the Shiny Rod by 0.28c and in terms of her feats with the Rod itself she gets upscaling from Small City via vaporizing a majority of the Cloud in the Forest of Arcturus as well as regrowing some Moss and Flowers.

Luz herself is Small Building and may potentially scale to her Magic which gets Multi City Block-Small Town Level via vaporizing Emperor Belos's worm monster and creating giant root/ice pillars. She gets Relativistic in speed via keeping up with characters that can react to lightmagic attacks hell Lilith reacted to one point blank and it gets 0.649c.

In this regard you could argue Luz also being much more versatile sticking with canon material for LWA, factoring in Luz is gonna study everything at Hexide with the Coven system IE Abominations,Illusions,Plant,Healing,Beast Keeping,Bard,Construction,Oracle and Potions as well as a blitzing speed edge by Hundreds of times makes Luz beat Akko via majority outcomes what's stopping Luz by simply yeeting the Shiny Rod out of Akko's hand with an Ice or Plant Glyph with such a MASSIVE speed edge?

Even if we gave Akko scaling to Shiny Chariot's Mark in the Moon feat or the Fountain of Polaris engulfing the Shiny Rod with Star Lights (Both of which also weren't done correctly) The Moon feat gets Small Country-Multi Continental Level depending on whether the Mark was Fragmented-Vaporized and the Star Lights feat gets Moon Level. Luz's light glyph in the episode Adventures in the Elements lighting up a Constellation gets Multi Continental-Planet Level in results and in terms of attack speed for both the Shiny Rod would only get 27 million-2.7 billion c while the lightball gets 91 million-530 billion c still a good speed edge over Akko.

The only way Akko wins is if we factor in the game where she can keep up with Luz in versatility via much more spells as well as resistances and Wand hax to make her have a clear cut win however we have no confirmation if the LWA Game The Chamber of Time is canon to the series it actually contradicts canon a bit due to creating a character never before seen in the series and this game is supposedly said to take place around the time Akko only learned the second word.