was working through the removal of NG TLS plugin. Looks like you must do a full config export, then
xmlstarlet ed -P -d '//*[local-name()="com.mirth.connect.plugins.ssl.model.SSLConnectorPluginProperties"]' fullexporttest.xml > engine.no-ssl.xml
then re-import. Otherwise some channels become uneditable. That is true with NG or OIE.
Credit to Paul C for finding this