Or revert sustain nerfs so heavy attacks won't be required for dps?
On the right track. Sustain nerfs went too far and lowered enjoyment level of the game. They should be reverted to some extent. Should they be reverted all the way to the level of pre-morrowind? Debatable.
Heavy attack builds were destroyed by the off-balance nerf with Dragon Bones. Before this off-balance could have near 100% uptime if there were a few Sorcs in the group, and all heavy attacks did more damage (about 60% IIRC). Now the off-balance uptime is artificially capped at 25%. This means on average 3/4 heavy attacks no longer get the bonus damage.
It’s also no coincidence that nobody wants more than 1 mag sorc in groups anymore. The group benefit of lightning damage has a hard cap, and most groups have switched to stacking as many nightblades as possible, while focusing on fire damage.