What do you think about Wholesale Electricity Price plans? Do we really save despite the fluctuating prices? Is the Price Cap Protector worth paying for?

At a glance, I think most people will not know about the Wholesale Electricity Price (WEP) plan. So, first up - definitions. These plans are not the ones offered by the retailers out there brandishing all those steep discounts in the Open Electricity Market (OEM)!
In contrast, you get the WEP plan from SP Group themselves.

What you do when on such a plan, is essentially paying the half-hourly rate at the moment you use the electricity. For example, if you use more at non-peak periods (with presumably lower rates), then overall you MAY actually save some money.

One of the use cases I can think of, naturally is those of people whose lifestyle/jobs are inverted to those of regular, working people, i.e. they use most of their electricity when most people don't.

On the Price Cap Protector, I can't actually find any information on it. Anyone else able to shed more light?