If the required WebExtension APIs don't exist (per nicoburns' comment) I'm not sure what you want the extension authors to do about it.
"Complain loudly" was the strategy that got Mozilla to implement Tree Style Tabs as a WebExtension feature so that the addon could be rewritten for FF57, but there are presumably still legacy extension capabilities that haven't gotten that treatment.
"Complain loudly" was the strategy that got Mozilla to implement Tree Style Tabs as a WebExtension feature so that the addon could be rewritten for FF57, but there are presumably still legacy extension capabilities that haven't gotten that treatment.