At a glance, it sounds as if those power stations need to pay for themselves in a few hours per week, and as soon as you get more transmission capacity from Scotland they're dead.
Give those constraints, of course they must be expensive if they are to exist at all.
however the market participants have "adapted" to it
https://www.theguardian.com/business/2025/jan/08/two-power-s...
it works pretty well on a short-term basis but due to the way the system works there's no ability to price-in a long term signal
the government is currently consulting on a changes to introduce this mechanism (as is the EU)