TOR_PT_SERVER_TRANSPORT_OPTIONS are not escaped according to pt-spec.txt
"TOR_PT_SERVER_TRANSPORT_OPTIONS" -- A semicolon-separated list of <key>:<value> pairs, where <key> is a transport name and <value> is a k=v string value with options that are to be passed to the transport. Colons, semicolons, equal signs and backslashes MUST be escaped with a backslash. TOR_PT_SERVER_TRANSPORT_OPTIONS is optional and might not be present in the environment of the proxy if no options are need to be passed to transports.
char *escaped_opts = tor_escape_str_for_pt_args(options, ":;\\");
Equal signs are not escaped. I'm not sure if anything will break with different behavior.