Perhaps...
The trouble is, on an old laptop with some 2400 compiled and installed packages over the years, pkg_rolling-replace can take weeks... and end up with several tens or hundreds of packages, which need to be done manually anyway. In these circumstances I often break the normal and otherwise right pkgsrc rules and use 'make replace', after making sure that at least the shared libraries which are to be used by the replaced package are available. Of course this breaks things from time to time, but not always; if I find myself in tight spot, I usually can downgrade a few packages and carry on for a while, or schedule a massive rebuild of the pkgsrc packages in use.
Anyway, it is a bit theoretical for me at this time, as my build laptop died a few days ago (the well=known NVidia substrate cock-up from a few years ago, on several T61p laptops over the years... ), so I'll have to find a different means of pkgsrc builds.