So the idea is to keep form -ve, right? But eventually you reach a limit as to how many minutes of exercise you can do in a week and a human limit as to how intense that workout can be, so inevitably your form will reach 0.
Then what do you do? Does it even matter, other than graph will be a scornful grey?
It all depends what you are wanting to do with your riding/training. Short answer is yes and no
Well, at this stage, I just want to out compete the slimy alien eating my lungs; maximise my lung function and VO2Max, I guess.
When you get to that higher level of VO2max, what do you want to do with it? Normally athletes use it for Peak performance before racing, or to get back fitness quickly after illness or injury.
Once the peak/race season is over, then the natural process is to let the fitness drop and see the form go into the +ve.
The point of the higher level of VO2Max, I suppose, is to compensate for my compromised lung function.
I guess therefore, there is no season for me, I’ll always be outrunning the slime, so then does my goal become to keep form at 0 and not let it drop? Which would require a horrible amount of discipline. I’m not sure I’m that tough!! 
Please give me some time to get a response compiled.
I’m busy loading a dummy plan to show how all factors come together, eg. current fitness (CTL), weekly load, multiple peaks through a season, etc.
Here’s a sneak peak so far.
The starting fitness is zero, to show how this affects the Form (TSB).
Ooh! How exciting! Thank you so much!!
