Disclaimer:
This may work for you, and it may not.   It's not a silver bullet, and you will still get 422's.   No 'optimizations' are performed.  All it does is globally limit the number of simultaneous connections to poloniex.    It currently has the polo IP hard coded, so if it changes -- you gotta change it.  It will redirect all local https requests to poloniex.
Requirements:
- 'nix server
- haproxy installed
- ability to edit hosts file
- port 443 available
Step 1:   Setup haproxy
This is a barebones, no logging, no frills config. 
global
   maxconn 4096
   user haproxy
   group haproxy
   pidfile     /run/haproxy.pid
   daemon
defaults
   mode  http
   option   httplog
   option   dontlognull
   retries  3
   option redispatch
   maxconn  2000
   timeout connect 10000
   timeout server 50000
   timeout client 50000
# Host HA-Proxy web stats on Port 3306 (that will confuse those script kiddies)
listen HAProxy-Statistics
    bind :3306
    mode http
    option httplog
    option httpclose
    stats enable
    stats uri /haproxy?stats
    stats refresh 20s
    stats show-node
    stats show-legends
    stats show-desc Workaround haproxy for SSL
    stats auth admin:nimda
frontend ssl_relay
    bind :443
    mode tcp
    option tcplog
    option socket-stats
    maxconn  5
    default_backend ssl_polo
backend ssl_polo
   mode tcp
   option tcplog
   balance roundrobin
   hash-type consistent
   server x_polo 104.20.12.48:443
-  Change the stats auth <user>:<password> to your liking.
-  If port 3306 isn't available for stats, change it to whatever you like
-  Set maxconn to however many maximum simultaneous connections you want
You can view stats at:   http://<yourserver>:3306/haproxy?stats
Step 2.  Redirect polo requests
Edit your /etc/hosts file and append the following to the end
<haproxyIPAddress>   poloniex.com
I'm sure there are some optimizations/tweaks, but it's a starting point.