I think the breaks you describe are perfect. You do not need to spend a week on the couch getting massages to properly recover in order to surpass a 280 watt ftp or 4w/kg. Maybe if you were years in and hadn’t taken any time off the bike at all and were in some mental/physical overtraining cycle, but clearly that’s not the case. I actually strongly disagree with all the people saying you need to take time off and reset or whatever. If you’re still mentally fresh and knocking out all your workouts, there’s no reason to do that.
I suspect you’ve seen a lot of improvements that don’t show up in the ramp test in percentage of threshold you can sustain for durations, repeatability…etc.
It’s more likely IMHO that you simply need to ride more. Low volume and even mid volume will only get you so far. People who have continuous improvements using low volume plans are typically supplementing with lots of z2 outside rides or unstructured outside rides. Time on bike is critical.