I found this amazing article written by user jomo and just made some scripts for self-usage.
First of all, edit files pf.tables/vpnonly-ipv4-hosts-allowed.txt and pf.tables/vpnonly-ipv6-hosts-allowed.txt - and add there addresses of your VPN servers.
Now simply run install script:
sudo ./install.sh
To disable filtering execute:
sudo ./disable.sh
To enable again:
sudo ./enable.sh