What are abuses of executive power that
the UK Parliament and parliamentary oversight failed to adequately safeguard against,
judicial oversight ought to be increased for?
Please list multiple ones! Please don't discuss Miller II  UKSC 41 that I already grasp. A unanimous UKSC ruled that Boris Johnson's prorogation of Parliament in 2019 was unlawful and void.
I don't think Miller I  UKSC 5 involved one. On the first point, just 8 of the 11 justices ruled that "an Act of Parliament is needed before Brexit can be triggered".
Of the three judges who dissented on the question of whether legislation is needed, Lord Reed gave the fullest judgment. He argued that EU law is not a source of UK law, but is rather a distinct body of law, and that the 1972 Act merely gives effect to EU law in the UK to the extent that the UK’s treaty obligations require. If, said Lord Reed, the UK leaves the EU and therefore no longer has any relevant treaty obligations, that will not cut across the Act. Parliament had not intended that people in the UK should have or retain any particular EU rights, merely that UK and EU law should be aligned for the duration of membership.