Why putty 0.70 ??

SSH und SCP Programmcode basiert auf PuTTY 0.70+
Copyright © 1997-2019 Simon Tatham

Why putty 0.70 ??

I have loaded WinSCP-5.13.9-Portable.zip

WinSCP 5.13.9 is based on PuTTY 0.70.
It includes only security fixes from PuTTY 0.71 (that's what the + and 2019 denote), but no new features.
https://winscp.net/tracker/1729

PuTTY 0.71 will be included only in (distant) future 5.16 (maybe even 6.0).
PuTTY 0.71 is the largest refactoring of PuTTY in decades, so it's going to be complicated to upgrade WinSCP.

thank you