I have a french Algerian briar sitter and a Comoy London Pride billiard (purportedly made of algerian briar per old print adv.) ... while the birdseye and grain do darken with smoking, only by a shade or two over time. These pipes are over thirty years old and no where near the rapidly accelerated colorization you are getting. I am wondering if this is not the result of your Linseed Oil coatings; Linseed oil does turn wood a yellowish amber color with repeated use. Its also supposed to be cured between 2 to 10 weeks to fully dry.
Maybe you should look at studying the effects of Linseed oil on wood. I do not believe Algerian briar has all of the attributes nor defects you ascribe to it. Just my two cents. YMMV.
Also, I have above average taste ability and have never tasted cinnamon in either pipe.
I’ve never put linseed oil on any of my pipes, but Marx may have.
Marx quit making his pipes sometime around 1953. And after November 1, 1954 the export market in Algeria was a war zone.
We’re discussing a dead briar source,
as for commercially graded briar.
I dug out an Edward’s, likely the last Algerian briar pipes made in large quantities.
It colors about the same as a Marx but it has very much fancier birdseye grain.
And it made Prince Albert zestier, more spicy, and it’s hard to describe it. Cinnamon is as close as I can get, but not a cinnamon roll. It’s subtle and not obvious, but it’s there for me.
There was something special about Algerian briar before 1954. Marx didn’t stamp Algerian on his pipes but most pipe sellers like Wally Frank and Lane were sure to say if the pipe was Algerian.
I suspect it was the cheapest.
Most people then and now want beautiful pipes, and they are hard to find made with Algerian briar.