Regarding innoextract - I was able to rebuild it against 1.72 with -DBoost_NO_BOOST_CMAKE=ON flag. According to relevant issues (innoextract, CMake), it's a problem with changes in Boost configurations and standard FindBoost script in CMake. The provided flag workarounds the issue by ignoring the problematic config file from Boost (see documentation).

Builded innoextract using git b47f46102bccf1d813ca159230029b0cd820ceff

source     :
     - git|https://github.com/dscharrer/innoextract : b47f46102bccf1d813ca159230029b0cd820ceff

CMake: Remove library link checks

This was needed with older CMake versions to work around CMake searching
under lib with -m32 instead of under lib32 for platforms where lib
contains 64-bit binaries. This has since been fixed in CMake and users
of older CMake versions can add the lib32 directories to
CMAKE_LIBRARY_PATH to work around the issue on their end.

With newer CMake and Boost versions these checks fail because the
boost-config.cmake files shipped with Boost use imported targets instead
of library paths and try_compile does not add these imported targets to
the generated project.

See: https://gitlab.kitware.com/cmake/cmake/issues/11260

Build successfully eiskaltdcpp with this patch. fix-build-with-pango-1.44.patch

diff --git a/cmake/FindGTK3.cmake b/cmake/FindGTK3.cmake
index 9017c0703..a933c6cfa 100644
--- a/cmake/FindGTK3.cmake
+++ b/cmake/FindGTK3.cmake
@@ -128,10 +128,11 @@ function(_GTK3_FIND_INCLUDE_DIR _var _hdr)
         gtkmm-2.4
         libglade-2.0
         libglademm-2.4
+        harfbuzz
         pango-1.0
         pangomm-1.4
         sigc++-2.2
-    gtk-unix-print-2.0
+        gtk-unix-print-2.0
     )
 
     set(_suffixes)
@@ -425,6 +426,8 @@ foreach(_GTK3_component ${GTK3_FIND_COMPONENTS})
         _GTK3_FIND_INCLUDE_DIR(GTK3_PANGO_INCLUDE_DIR pango/pango.h)
         _GTK3_FIND_LIBRARY    (GTK3_PANGO_LIBRARY pango false true)
 
+        _GTK3_FIND_INCLUDE_DIR(GTK3_HARFBUZZ_INCLUDE_DIR hb.h)
+
         _GTK3_FIND_INCLUDE_DIR(GTK3_ATK_INCLUDE_DIR atk/atk.h)
         _GTK3_FIND_LIBRARY    (GTK3_ATK_LIBRARY atk false true)

@algent and others you can submit the patches directly just add Depends on D8527 in the summary.

mygui can be removed from the rebuild list, because as of R2125:9c87bcdd1cf8d8692f89a4089955f3317a5ffed8 it no longer depends on Boost.

So only two left here rstudio and vcmi.

VCMI is tricky one. Its master branch should build against latest Boost, but its last release differs too much from the master, so patches for Boost compat don't apply cleanly. A lot of code that breaks with latest Boost was completely removed from master years ago, so we have to patch it ourselves if we want to continue with release sources.
And mainteinance of project isn't very good - apparently they attempted to issue 0.100 release last year, but for some reason it stuck and there is no sign of ETA for it.
Moving to master would be the easiest way to get compat with new Boost, patching 0.99 codebase require some knowledge about VCMI engine. Or maybe someone else has already patched this and we could incorporate the changes.

I have submitted a patch for rstudio to build against boost 1.72. See D9012

Maybe include latest Master of VCMI with a release version like 2006 (yymm)? Or deprecate it and wait for a new release. I would go for the first version. VCMI is not badly maintained...they just have bad release management (none at all?)