This is a very good argument. I know stopping at combos with multiple wobbly genes is kind of arbitrary but this is my logic for using that as a stopping point.
I've heard spider is the gene with the worst wobble (that could be wrong) but I've seen plenty of spiders that seem to be fine (of course we can't know for sure as you stated). To me it doesn't make sense how two genes that both cause wobble couldn't make it worse (unless they cancel it out entirely). Regardless of whether it's an additive effect or a multiplicative effect it's just not something I want to do. The animal might seem completely fine and appear to thrive but it seems immoral to me.
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