It can be done effectively and safely. It can result in a breakaway and a win. So yes.

Anytime you can cause your opponents to have to accelerate more than you (greater change in speed in less time) that is more power and energy they had to use than you. It adds up. The brakes are tools to help with that. Brakes in corners even more so.

The best way to ride a TT corner, or any TT section and even lines followed may not be the best in a road race or crit. Smoothness, shortest route favors the TT but used and on the road gives your opponents a nice wheel to draft - and looks cool in video.