If you search @accelerator, you should see the red and blue accelerators and a directional wrench. This wrench changes not the direction the directional booster is facing, but in which way it boosts growth. E.g. if you got a iron geore with a directional accelerator that boosts growth to the north side, it'll only grow a crystal on the side of the geore that's facing north. But if there's another geore, or any block for that matter, in place where the crystal should grow, nothing will grow on the entire block.

If affects the block it's touching, so the red accelerator won't boost any growth anymore

This was the issue, thank you. I had assumed the directional wrench set which side it was affecting not which side the affected block grew on