I wouldn't worry about it, bro.
Over 31 years of expert witness testimony in weapons/shooting cases, I can't say I've seen it all. However, I've seen a lot. I've seen custom grips argued as a reason to believe that the defendant was obsessed with killing people, and also the argument that smooth grips (finger grooved, no less, in that case) were reckless because they caused the shooter's hand to slip and accidentally discharge a weapon.
That said, when that sort of BS comes up, a well prepared defense team shouild be able to utterly destroy it with expert and material witness testimony.
Get your gun to where it works for you, be able to explain clearly why you did so, and I for one don't think you'll have much to worry about. For what it's worth, my personal favorite Glock is a G30 with a grip trim done by Rick Devoid at Tarnhelm, www.tarnhelm.com
, and another that I carry often is a G17 with Tac-Grip (www.tac-grip.com
Just one guy's perspective,