As 19.07.x is EOL, there won't be any changes/ fixes anymore - not that there would be a fix to these size issues to begin with (other than disabling the affected devices from being built).
(Marking this thread as solved, as there is nothing to 'fix' anymore - 19.07.x is EOL, 21.02.x+ doesn't support 4 MB flash devices anyways, considering average firmware sizes just shy of 6 MB)