Yes, underspin when I overswing my rightie serves using eForehand grips.
But very controlled when the swing is moderate, and I get sidespin on the second serve just fine, but not topspin.
However, if you play tennis THREE times a year TOTAL, why would you want to learn a conti grip right handed service grip?
Oh, I can throw a football right handed about 35 yards without any warmup or practice. It's a wobbly mess, compared to my lefty throws.
And trying to hit a ball is a whole lot harder than shadow swinging. However, a righties serve for me is a lefty toss, so it's super consistent first try and foreever.