How common is for presidential term extensions to be bundled with other issues in referendums?

By presidential term extensions, I mean broadly measures like: allowing more terms than before, extending their length, and even allowing special purpose measures that effectively apply the previous two kinds measures to specific people by "disregarding" some previous terms.

Such issues are often enough enshrined in constitutions that require referendums to amend. And amendments by referendums are generally costly to organize and less flexible in their scope than changes via representative systems because unlike a parliamentarian, the "average Joe public" voter can't easily propose a last minute changes to the provisions on the ballot.

So, how common is for such measures regarding presidential term extensions (as defined further above) to bundled with other issues in a "take or leave it" package of constitutional reforms, subject to a single referendum question?

I'm mostly interested if there's a reasonably formal surveys of such "bundled" extensions relative to cases where the term extensions could be voted on individually/separately (such a survey would necessarily be across countries, since a single a country won't have that many of these events).