Hey guys, I wonder why A-Train's scene saving The Boys team in Season 5, Episode 1 is considered an outlier, even though he later managed to outrun Homelander, whose flight speed reaches up to Mach 1.51. After receiving his heart transplant, the storyline never explicitly stated that his powers increased, nor do I recall him secretly training like Queen Maeve did in Season 3.
My assumption is that he didn't take Compound V to boost his powers like he did in Season 1, where he used it out of insecurity regarding his race against Shockwave and his fear of being kicked out of The Seven. Therefore, during that race, he had to push himself to his absolute limit to defeat Shockwave, clocking a top speed of 371 m/s. Fast forward to Season 5, Episode 1: in the scene where he was running for his life from Homelander, I believe he must have been running at his absolute maximum speed as well, since capture meant certain death. Similarly, Homelander must have been flying at his top speed out of sheer rage over A-Train's betrayal and his desire to kill him.
Since both were pushing their limits, they chased each other at comparable speeds. However, their official top speeds do not match; Homelander's is Mach 1.51, whereas A-Train's should be lower than 371 m/s because he wasn't on Compound V. This seems entirely inconsistent.
Is it possible that his previous drug addiction prevented him from pushing to his super speed mode during the race—unlike when he rescued The Boys team from the internment camp—due to the severe toll it took on his body? But once he got the new heart, he could access his peak speed again, albeit briefly because it drains too much energy. Consequently, the speed he used to escape Homelander was just what he deemed sufficient to keep drawing distance without burning out. As for the scene where The Deep dodged his punch in Season 4, I assume A-Train didn't intend to kill or fight seriously; he was merely holding Deep off so Butcher’s team could escape.