Is this just a bad idea or an opportunity for somebody?

A low speed compression damping circuit does the job just fine on my lyriks.

great – apply the brake and have the suspension stop working

next thing your front wheel is off the ground and you have no braking 😀

Good suspension, properly set up will have slow speed compression that can be adjusted to suit the rider/bike/terrain. Then you wont have a problem.

Some small dive is a good thing as the weight transfer improves braking efficiency.

Too much is a sign of too soft forks with little or no slow speed compression. If you set your forks up by bouncing them round the carpark then your very likely to have them set up too soft and end up with massive dive. Some forks just dont have slow speed control. My old Mavericks were like that.

Also, dont forget the biggest weight is the rider, and it should not be a static weight on the bike.

Isn’t that how the BMW Duolever front suspension works on some of the motorcycles?
Involves a linkage and shock rather than telescopic forks but reduces brake dive considerably.
Is the Whyte PRST similar to this?

It’s probably not what the OP was thinking of with fork lockout though, but this is one solution to countering brake dive.

USE SUB anyone ?

forks that lockout when the brakes are applied ?
i don’t think mr oxford thought this through properly.