Hi,
It seems that building these packages requires some non-trivial work, which I would rather not dive in. At least not now (I do not even have RPI3/4 at hand; RPI-Zero-W is my target). Maybe I will get back to piCore and try to build missing packages, but for now I'm gonna look for a ready to use solution. Alpine is my next choice after Rasbian (which has its own problems) and piCore.
Thanks for the input and links. I will keep them in case I can not find out something that can be used out of the box. Paul, if you can help with any of these packages I would appreciate.
BTW, I really like the idea behind Tiny Core. It looks really solid. It took me (a total newbie) under two hours to set up my Raspberry Pi Zero W to work simultaneously in station and AP modes. Unfortunately, without iptables I can not test, if it can reliably work as a WiFi extender. And without dnsmasq (or other dhcp server) and some MQTT broker I can not easily set it up as an IOT hub.
Anyway, thank you for all your hard work.