As long as the hydraulics don't leak down that could assist in certain areas. I used a tractor bucket to hold something in place once, after going around with my water level I came back to my bench mark to find it was not right....back around to see where the issue was, when it was the bucket settling. The tractor bucket was holding my water level bucket, that was a half hour well spent.
The chart, sizing gin poles, is that for a specific angle, say a straight vertical lift? Or can the pole be tilted or the load lifted from a distance, inputting different loads on to the pole? What does the chart really tell us?
Tim