Para and graphic EQ gain range of 20 dB

most guitar EQs do at least 15 dB, good ones do 18 or 20 dB (MXR 10 band, EQD Tone Job)

while true, they don’t do it well - most of them clip well before reaching that level. But a digital EQ has the same limitations with respect to clipping, but yes - 20 dB should be within reason I think