i figured out late last night how to enable telnet on the WL-WN570HA1 thats running 190220 firmware. There is a hidden web page at http://192.168.10.1/webcmd.shtml. once you are on this page type telnetd into the command box and press the apply button. nothing will show up in the lower box as a reply but if you port scan the device you will find port 2323 is now open for telnet. the default login=admin password=admin.
its still limited on what can be done because of limited commands like no wget but its another door into the device that could lead to something. This may or may not work on other firmware revisions but it definitely works on 190220.
The link below is to the Wavlink WL-WN570HA1 190220 firmware. you can upgrade to this through the default firmware upgrade page. https://drive.google.com/open?id=1PlySf2y8X1vHCdl4wZT8hUtIO4QxcmHw