If 5 on 3 off or 4 on 4 off doesn’t suit for £35 grand then self employment certainly won’t! You’ll do 7 on none off (including the two days “rest” you spend worrying about your predicament).
Tarmac will expect “flexibility”, eg, “you’re doing nights tomorrow” only to have it cancelled/moved hours before the event. I’m now on 4 on 4 off and I’m in nirvana compared to my old life in the weighbridge bread queue…plus I get a pension, sick pay, paid holidays, work clothes laundered, a mess room, BUPA and not whistled at like a dog or treated as a lower form of life.
Your choice mate but I know which option I’d take