I don't know in your situation I might try to find a male in the same egg group with SD and use in as a parent for awhile but then that means you have to build back up to 4 or 5 31 IVs again.
But then again the RNG may go ahead and give you the SD in the next few eggs.
That's a question I don't have a good answer to...
If it were me I thin I'd just keep breeding a hoping...