[Selling actual inventions wasn't anything new, even if the majority of Hiccup's contraptions were widely ignored, but an idea? Most vikings weren't too keen on taking the time to read design instructions, even if they had the proper skillset to put the thing together.]
Your guess is right. That sort of thing can happen back on Berk, but it's not exactly likely.
I'd imagine it's probably not that likely here, either — there isn't that same sort of intellectual marketplace of ideas that he and I are used to. So if you choose not to write your secrets in code, simply not sharing your notes will probably suffice to keep them safe.
audio; | cianwood city | october 21
Your guess is right. That sort of thing can happen back on Berk, but it's not exactly likely.
audio; | cianwood city | october 21