TOR_PT_SERVER_TRANSPORT_OPTIONS are not escaped according to pt-spec.txt
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.
or/transports.c:get_transport_options_for_server_proxy()
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.