The bike algorithm is very simple… it runs at level N, and the pulses run at level 2*N. So, if it’s set to level 40/150, the pulses flash at level 80/150. However, it doesn’t limit the brightness to halfway up the ramp. It doesn’t stop at 75/150. The default allows it to go up to 120/150.
So it should then pulse at level 240, but there is no such thing. The light itself can only go up to 150.
In other words, no, I can’t make it brighter to make the effect more noticeable. It’s already going as bright as it physically can. If you want the pulses to be more visible, you’ll instead need to turn the brightness down. Like, instead of running at 120/150, maybe try turning it down to 90/150. Either way, it’ll pulse at 150/150, but that will look more noticeable when the base level is lower.
That … may be a bit excessive. Tail lights are usually not thousands of lumens. It’s likely to anger people behind you.
Have you considered using beacon instead? It has adjustable brightness and can run at 1 Hz…