Yes. Preferably several times to allow the oil to harden between applications. What you want to achieve is preventing water absorption, which occurs through the same capillaries that absorb the oil. An oil that hardens functions both to prevent water from sticking and as a plug in the capillaries.L Leaff said:
When I've replaced a panel, I've screwed a board/stud at the bottom as support, meaning I haven't cut afterward. Oiling/priming becomes better/easier/faster. But it also depends on what it looks like at the upper end of the panel being replaced (midjeva, just under the roof overhang, etc.), what precision is needed.