How to retain a custom build kernel?

@cynerd once having build a customised kernel it is not clear to me, after perusal of, how to retain the customised kernel and not pulling the kernel fed by the TOS repo feed with pkgupdate?

You are going to get core repository with packages. That one contains all kernel packages. You have to deploy it somewhere and add it as a feed to updater with higher priority than turris ones (those are priority 50).