I have a Theirs Issard 5/8th. Marked acier c135 ( via art of shaving)

I understand the newer steel formula is supposed to be harder and harder to sharpen.

I think I’ve spent 2x the time on this razor, While it is a passable shave, it is not as sharp at the rest of the razors in my stable.

Did I find the max sharpness for this steel?
Keep on honing?
Any suggestions?

(Finishing on translucent ark)