As a short length of feeder, RG316 and even RG178 are probably fine. However, my experience is that the outer jacket on these types of coax is very thin and fragile. It’s not a major factor for us in SOTA (my portable End-Connected Windom is still going strong), but it is not really suitable for long term outdoor installations.
I have had 2 End-Connected Windoms start to leak through the jacket and the copper braid has corroded. The antennas still work but it’s not ideal. I reinforce these types of coax with clear heatshrink if I am winding them on a ferrite. For a home station antenna, normal RG174 is probably better as the jacket is far more UV resistant. Thankfully, I still have plenty of DXW174 in the attic; I do hope they get some more in stock, it’s ideal for us SOTA activators.
73 de OE6FEG
Matt