OK, well I finally got stung into action. BF is now 64 bit AND 32 bit compatible. And, to keep things simple, there is still just ONE installer (bf.exe) that installs for all versions of Excel from 2000 onwards, 32 and 64 bit.
Internally, there are actually 2 xll's, Busfunlb.xll and busfunlb64.xll and the VBA loader decides which one to load by querying your installation of Office. It seems to work fine.
The compiling for 32 bits and 64 bits has a benefit in that compiling for 64 bit actually flushed a nasty bug out of the system ie a bug that had me stuck for 2 days! It was to do with coercing using variable argument lists in C++ which for some reason the 32 bit version was tolerating. So its made me more rigorous, no bad thing.
I haven't been over the code with such a fine toothcomb for years, and I was actually enthused by what I found, and I would love to put up some more examples and educational materials.
I use the 64 bit Excel myself now, and I like it - it feels nippier.
Other than that, the release just updated the compiler, boost library and retired the seasonality functions because I am not really sure that they ever worked properly.