Speed difference on Gemma 4 26B-A4B between Bartowski Q4_K_M and Unsloth Q4_K_XL

I've noticed this on Qwen3.5 35B before as well, there is a noticeable speed difference between Unsloth's Q4_K_XL and Bartowski's Q4_K_M on the same model, but Gemma 4 seems particularly harsh in this regard: Bartowski gets 38 tk/s, Unsloth gets 28 tk/s... everything else is the same, settings wise. This is with the latest Unsloth quant update and latest llama.cpp version. Their size is only ~100 MB apart. Anyone have any idea why this speed difference is there?

Btw, on Qwen3.5 35B I noticed that Unsloth's own Q4_K_M was also a bit faster than the Q4_K_XL, but there it was more like 39 vs 42 tk/s.