I got some user report that the using the net backend for .14-r6 resulted in some hangs, whereas he had no problem with .15 - so perhaps you could consider removing the ~ in front of amd64 if you don't know of problems with this version.
Created attachment 52290 [details, diff] sane-backends-1.0.15.ebuild Would also vote, to mask this stable on amd64. At least emerges cleanly. Also, ieee1284 support should be added, please apply the patch. The libieee1284 is already masked stable on amd64.
it's already stable