How to configure multiple SOCKS5 ports on different network interfaces?

Question

SSH

There is such a task, there is a laptop with several 3G modems, you need to create a SOCKS5 proxy port for each network interface and forward it to the server, incl. connecting to the appropriate ports on the server, the packets exited the modem interfaces on the laptop.

I wrote this script https://pastebin.com/0y6ECN1e

which creates users and generates iptables configuration, here is an example

https://pastebin.com/ysXfv3gS

But in this scenario, if I do just
$ sudo runuser -l [email protected]
$ ssh - D 22102 localhost

and then
$ curl --socks5 localhost:22102 check-host.net/ip
then the connection just falls off by timeout

What am I doing wrong? How do I fix the routing table so that my example just works? Then I plan to forward it through
$ ssh server_ip -R 10102:localhost:22102
and already use
$ curl --socks5 server_ip:10102 check-host.net/ip

who will undertake to implement this in a short time (today) is ready to discuss a decent payment.