Yes, do resign now. Send in by email. Good plan, every reason to believe your hopes will be realised.
This below is what poc has written to another poster. I copy here as he understands best.viewtopic.php?f=2&t=50969#p129432Does removing name break sealings? Yes to my understanding.
Even if ex is still active? Yes to my understanding.
The sealing has a His, Hers and Theirs parts/blessings. The removal of his name eliminates the His part of it and the Theirs part. The Hers part is not affected.
And as Rain says, it only matters if the LDS priesthood has any power and isn't really a made-up thing. Though even if it is made up, we often give things power by our thoughts. She will be bound to him if she thinks she is bound to him.
You do not need to mention or request voiding a temple wedding. You will have done all you can in resigning.
Do get back to the Board if you'd like to.