Aside from the formatting (s/True/true, s/False/false, missing spaces etc), shouldn't it say SUMMARY true? I've cleared the browser and bundle caches, rebundled etc.
I think I misunderstood the documents - https://www.postgresql.org/docs/12/sql-explain.html. Few of the parameters are applicable only to EXPLAIN ANALYSE and not to EXPLAIN. Will make the changes, along with formatting to existing codes as well.
Attached is the patch to add support for SETTINGS(v12+) and SUMMARY(v10+) explain options. These options will be visible only if version is supported.
I have also created and fixed RM4395. The explain options changed on one query tool should not change explain options on other query tools or preferences. The initial values will be taken from preferences are usual.