The main constraint in increasing the C/L dose is whether it leads to dyskinesia. You don't mention this in your post, so there's a good chance that it is not a problem, and so you can increase the dose. You should aim to have the flutuations between the doses as low as possible.

You should discuss with your doctor a regimen of five doses per day, each of 300 mg, and three hours apart. This gives you more spread over the day. You should titrate up, starting with the first dose of the day. As the concentration rises through the day, as the left overs from one dose count for the next, you may find that the later doses are not needed or can at least be reduced

Rasagiline is also worth considering. It gives, in effect, the equivalent of 100 mg C/L, but in a spread out way, so it is useful for laying the foundations of your daily regimen.

John