The four hole is it. If you go much past it the support rod will separate (not irrepairable, but not good). Mine also needs to be in fourth hole for the door to clear. I drop the end of the awning opposite the door to third hole when rain is coming. This is necessary for rain water to drain properly. If you don't do this large amounts of water will sit in the awning.
SuEllyn & Brian McCabe
WBCCI #3628 -- AIR #14872 -- TAC #FL-7
2015 FC 25' FB (Lucy) with HAHA
2020 Silverado 2500 (Vivian)