is half rim eyeglass frame difficult to cut the grooves with low prescription?

[glasses lens]

someone tells me that if your RX is too low, so that the edge of your lens will be very thin with the half rim, it's difficult to cut the grooves along the edge of the lens, especially if you want a large frame, I suggest you should try rimless frame or choose a smaller one. I come to a local glasses store for a pair of reading eyeglasses, the SPH is only +0.75, the optician told me that it's hard to fabricate the glasses for me with half rim frames, any one can tell me why this happens?