I have never cared that much for BLO as a wood finish. Maybe I did get the right stuff or use it properly.
I have lots of boxes that haven't been finished w/ anything. They seem to be holding up just as well as my painted equipment. Though most of my painted equipment is alot older than the nonpainted equipment. I'll still bet that it will out last my lifetime.
I know beekeepers who paint the insides as well as the out sides. I don't know anyone who uses BLO. Which doesn't say much, one way or the other regarding your question. Sorry.
I use it on all my equipment. It takes longer to apply then paint. Alot of brushing, letting it soak and absorb, hand rubbing. Boiled linseed oil is probably a labor of love for your bees. My opinion is that it is healthier then any paint or stain you can put on your woodware. Here's one method keepers use- mix 1 to 10 ratio of beeswax, linseed oil. Warm them both up until they mix well. the rain will bead off the wood like waxpaper. Just remember, to look and work well, it is labor intense.