Hi @kopf,
Yes, email variables/templates changed significantly with 3.4. You can see some more detailed info on that here: https://docs.pkp.sfu.ca/learning-ojs/en/about-ojs#whats-new
One piece that might be particularly relevant, given what you’ve noted is that:
Each email comes with a glossary of available variables that can be inserted using the ‘Insert Content’ button. The values of variables, such as the author’s name, can be previewed before the email is sent.
This way you should be able to easily identify variables that can be used.
Not that I know of. Variables are very much dependent on the particular email template being used,.
This thread, although a bit dated, does explain this to some degree: Email variables list - OJS 3 - #6 by astevens
But unfortunately, there is no master list of variables, to my knowledge.
-Roger
PKP Team