As I see it, the 26 week option is to cater for any sector(s) of the Industry where there is a seasonal variation.
Typical examples might be the Building Trades suppliers, Domestic Fuels & Gas deliveries.
I think you said you were back on skips. You will know better than most of us whether the work demand follows any predictable fluctuations.
I suggest the main problem with your employer is communication.
What many drivers seem to have failed to grasp is that whichever system is utlised, when the employee has reached 712 Working Hours (in a 17 week system), then, if that happens in week 14 or 15, then he must be laid off. I.E. Can’t be used for other tasks, can’t go Agency driving, can’t take Holiday, and if the reason for those hours being accrued is because the driver himself has failed to record non-Working Time accurately, then employers will be treating that as Negligence and withholding pay.
It’s not going to happen in every case, but there is a strong argument for employers to adopt a “Basic + Bonuses” structure which will hit those less detailed (and possibly inventive) in their Time Management recording.