The chrome://flags/#infinite-session-restore flag has been removed since chrome 74, but I found that the “Restore pages?” can still be avoided by starting Chrome with this parameter:
--disable-session-crashed-bubble
I post this here, because I guess it can be useful to others as well.
The other options that works for me is to use the “-incognito” flag. It seems this flag disables the “page restore” dialog automatically when used 
Yet another option I found is to simply use XClickRelative at the start of my macro. It searches for the “Restore pages?” dialog and closes it if it is found.