Avalanche of Sector 7 needs to trigger on mana abilities also

Looks like trigger on activated ability only looks at stack object, which is fine for most cards that specify "that isn't a mana ability" but [[Avalanche of Sector 7]] doesn't have that restriction, so its trigger needs to be broader

Start by tracing the activated-ability trigger handling that currently checks the stack object, then inspect the implementation of Avalanche of Sector 7. Verify how mana abilities are represented and run the relevant existing card or trigger tests. Done means Avalanche of Sector 7 triggers for the applicable mana abilities as well as other activated abilities.

Written by the indexing model from the issue text.