Pretty much – the one on the left is a KH 25.4mm pivotal seat post and the one on the right is the Mad4One XXL I was talking about. As you can see, this KH one is similar to your one internally (I have other KH offcuts where the inside is perfectly concentric). The Mad4One centre is more round, just offset a bit.
However, the KH one has around 0.02mm variability in its diameter (rotating it in a pair of digital vernier callipers not measured with a dial gauge). The Mad4One has a bit over 0.1mm variation not just on roundness but also along the length – the maximum is just over 27.3mm.
So 0.1mm isn’t much but it caused it to bind in my frame whereas two KH seat posts I tried fitted fine. Reaming it to 27.4mm as Jakob suggests would probably sort this out for me and I don’t need to mess up my nice M4O seat post. So in this case it is probably a combination of the frame and the post that caused it to bind. As I recall it started to bind when it was in the frame a little bit beyond the slot.