I went a few pages in and never found a V-bit in anything but 60, 90, 120, and 150. OK, Amana makes a 45 total included angle insert bit, I did forget about that one.
Engravers are “V”-shaped, as are tapers, but they’re different in nature and use. Notably, they are acute angles (<30 deg) and this do not have substantial width, and generally intended to engrave with the tip Case in point- bits under the term “engraving” wouldn’t likely bevel as needed here.
The original question being “can I bevel to make box corners at other than 90 deg?” I interpret in a more general sense as looking to meet a design’s arbitrary angles, rather than limit to the (45),60,90,120,150 options.
Arbitrary beveling angles can be done with an end or ball mill and multiple passes stepping down- it’s slow, and, again, stepped thus not a true bevel. But it’s an option. It could do different angles without another bit change, too.
I’ve never seen an adjustable-angle bit, nor is there a method I can think of to use any bit to create arbitrary true bevels except a tilting head or other multi-axis machine setup.