Morning Simon,
Therein lies the problem. It is the 'high performance detergents and cleaning agents' that manufacturers claim to be added to the oil that would concern me. By definition they must be more aggressive than the detergents in normal oil to be of value.
My thinking is that if an engine has had a regular pre-oil-replacement flush throughout its life then there is no harm in continuing with the practice or stopping it as the engine gets older.
It is when the engine has not had such a treatment from new or near-new that I would worry about using a dedicated flushing agent. My approach would be to use a mild flushing agent i.e. normal oil. But this is a personal preference as opposed to a statement that this is the best approach.
Amsoil, who produce oils and flushing agents, have a useful and I feel balanced write-up on their website here.
https://amsoil.eu/blog/is-an-engine-flush-good-or-bad/
Maninder.