The % genoa will depend not only on the LP, but the sq footage too, depending upon if you race. Here in PHRF-NW the 150 is 150% of the 100% foretriangle. IE we use actual sail area around here from a rating stand point,
Some manufactures like Jeanneau, currently use a max of 135, and that is designed to be the largest headsail. BUT< to get to a 22-1 SA/Disp for decent performance of the boats, they use a larger main than one would if a boat is designed with a 155 max head sail like my boat. Some boats like a C&C 115, X yachts and some Hanse's, the max head sail is a 110, they are fractional setups, and as such, have HUGE mains in relation to my boat as an example. My 155 is 345#< where as my main is only 195. Where as some boats will be the opposite, a main of say 345, but a 110 jib of 195, giving you 540# on a 6500 lb boat and a 24.5-1 SA disp.
Now from the OP's std point, some boats I would surmise to call a 120-140 a working genoa, something bigger than a 110, ie std typical max for a jib but smaller than a 155 or for some boats back in the late 60's and early 70's designed for the IOR rule, would use head sails in the 160-170 range.
Today most would use an Asymetrical for when you wanted a BIG genoa in the 170 range as mentioned. I can point upwards of 55-60* with my AS.
She drives me boat,
I drives me dinghy!