i think you already know your answer, but if you have a specific area you want to improve (call it 5-8' power specifically on flat courses), then you need to train the ability to make power for those durations at the leg speeds that your gears/terrain dictate.

we could have a whole discussion around how to improve power for X duration (which doesn't always involve intervals of that duration), though again i think you know those methods. the key is to train in the right quadrant -- in this case, high power, high cadence.

in a flat course/no wind, your best bet is going to be to ride as steady as possible THROUGH every feature. if we add wind, then that changes things--and that is where a time trailing background/experience (or at least being very tuned in to where stepping on the gas just a bit more and easing off just a bit) can shave a few seconds and mean you make the connection vs going back to the pack.

also, can you do anything to improve either your equipment or your ability to handle any technical elements even *slightly* smoother than the group ahead?