Is there a way to change the crt range for certain refresh rates?
Sure. E.g.:
crt_range0 15625-16200,
49.50-55.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 192, 288, 448, 576
crt_range1 15625-16200,
55.10-65.00, 2.000, 4.700, 8.000, 0.064, 0.192, 1.024, 0, 0, 192, 288, 448, 576
(obviously, changing the rest of video timings so you have 2 effective ranges where different params apply)