yeah… looks like I had read an article which referenced a study by skiba et al, Modeling the expenditure and reconstitution of work capacity above critical power - PubMed
Which includes this table:
the estimates for my W’ vary between 21-22 kJ, which is at or slightly above the mean from that table, but I also weigh almost 10 kg less than the mean weight of the subjects, so I’m not expecting to gain much in that aspect. Raising FTP seems like more of an achievable venture.