Judging from the GNU findutils change log it had to be in GNU's find for at least a decade (also longer than that it was part of POSIX) so can it be safely assumed to be supported everywhere now?
Also, are there any good reasons to advocate for
xargs instead in cases where
-exec … + could be used? (Obviously you would use
xargs if you need some of those special parameters like e.g. those for controlling the maximal number of arguments, parallelism, …)
An interesting quote from a part of GNU findutil's documentation:
-exec … +] can be less efficient than some uses of
xargs; for example
xargsallows new command lines to be built up while the previous command is still executing, and allows you to specify a number of commands to run in parallel. However, the
find ... -exec ... +construct has the advantage of wide portability. GNU findutils did not support ‘
-exec ... +’ until version 4.2.12 [January 2005]; one of the reasons for this is that it already had the ‘
-print0’ action in any case.