I would actually advice *against* doing that. It creates more problems
than it really fixes. What DragonFly is doing in contrast to NetBSD is
to basically ship a pre-bootstrapped system. Including working versions
of many of the core tools is fine, but pkg_install is quite likely to
create issues on the next round of changes that with forward
compatibility.
Are you advising against adding pkgsrc as a program to the base system or against shipping a pre-bootstrapped version? Also what kind of changes are being planned?
Feel free to contact me if you run into problems with any part of the
core infrastructure, BTW.