I'm taking baby steps and try to get everything right from the beginning.
Having considered Jon Dart's suggestion and examined a few open source engines (GreKo http://greko.110mb.com/ is a favorite) I decided to add the notion of not standing pat in the quiescence search if in check.
That required continuing for one step and a need for check evasions.
My new check evasion code takes about a fourth of the time compared to the old one, which seems nice. And there might still be a few more optimizations to do.
Last bug a squashed concerning it was evading a check by capturing to the last rank and promote to a non-queen.
How I've missed these ultra-specific bugs... :)