[NTG-context] names of cached images

Hello list, using conversion=gray.pdf in lmtx the cached images' names have some string in their name. I thought it's a name of random sequence of luatex cache, but the string is the same on other machines and I don't know, where it comes from. mkiv used to have m_k_i_v_ string there. hacker.pdf = source image hacker_jpg_c60ccda70ef92e32d7a6334f31c23259.gray.pdf = cached linux hacker_jpg_c60ccda70ef92e32d7a6334f31c23259.gray.pdf = cached win MWE \starttext \externalfigure[hacker] [cache=./, conversion=gray.pdf] \stoptext Is it intended behavior? Thanks, Jano