I have one more post for today, so let's sum up my spamming(again sorry for it, i just got too excited with getting over OS's stupid iptables clone).
1). Enabled sharing internet to my device (Ax88x72A)
2). Changed IPs as shown in the first message of this topic, but put OS's en9 interface MANUALLY a 192.168.2.1 address
3). Changed Pineapples gateway to 192.168.2.1
4). Executed this pfctl rules in terminal:
# enable IP forwarding
$ sudo sysctl -w net.inet.ip.forwarding=1
# enable PF firewall
$ sudo pfctl -e
# Add NAT rule after en9 is up (Pineapple already plugged and started)
$ echo "nat on en0 from en9:network to any -> (en0)" | sudo pfctl -f -
I am sure, that you don't need to change the subnet, as you just nat everything from en9 interface to en0 (wifi interface).
Just make sure that your usb interface (en9 in my case) and pinapple gateway are the same.
So a packet from pineapple goes to gateway (ex. 192.168.2.1), then it is being nat'ed by OS from en9 interface to en0 interface.