So I'm pretty sure I'll be fighting against some Autoblaster AC Nym, needed to know a ruling. Does Omega Leader's ability disallow TL'd ships to use Accuracy Corrector?

No, it does not disallow the ship to use Accuracy Corrector, but it will do nothing. The ship will cancel its dice result and then Omega Leader will prevent it from adding two HIT result.

Cancellation is not a modification but adding is.

2 hours ago, muribundi said:

No, it does not disallow the ship to use Accuracy Corrector, but it will do nothing. The ship will cancel its dice result and then Omega Leader will prevent it from adding two HIT result.

Cancellation is not a modification but adding is.

To put this another way there is nothing stopping you from using Accuracy Corrector to cancel your dice results but Omega Leader can then prevent the ADDITION of two hits.

You can use it but you probably will not like the results of its use.