[NTG-context] Which version of MkIV should we use?

Hello all, I have noticed some differences between the MkIV installed as part of LMTX and the MkIV installed via first-setup. Which should be used going forward when one wants to use MkIV? (One difference: \contextkind is defined in file context.mkiv installed via first-setup. It is not defined in the file of the same name installed as part of LMTX. Another, more significant difference, is loading modules.) -- Rik