I always look before crossing the road. I always look before joining the circuit. If an aircraft is climbing in the circuit, he has right of way. If there is any chance that I may cut in front of him onto the downwind leg, I would extend upwind and go behind him. There is no problem extending upwind to do so. There is also no problem in using the radio to announce it, btw!
Imagine two high wing aircraft, one joining, one climbing. The pilot of the one climbing will be blind to one above and to his left, especially if that aircraft is slightly behind (and catching up due to higher airspeed). The one joining and turning crosswind will be blind to aircraft below and on his right....
To risk cutting in front of an aircraft already in the circuit, to some "pre-programmed" standard pattern, with no flexibility or forethought is terrible airmanship.