So just posting here for reference, in the future, if someone is interested.
I took the dropper seatpost out, placed a big flashlight in front of it and saw that there's a small bump in the frame. The exact bump depth is 350mm, meaning - that's the maximum insert (minus few mm).
I made my mind to take a PNW dropper instead (30% less and offers more of less the same experience.) - I'll update here how the 170MM PNW works and if I need to reshim it.
Cheers,
Mor