You are correct, some day you will need to be able to lift just a tad more and need to remove all possible FEL weight.
My tractor has a different front configuration than yours, but I have dropped the bucket to get sufficient lift capacity before relief valve pops. Made a BIG difference in what I could lift.
When the time comes, I recommend you use chains attached where ever you can do so without damage to hydraulics. The hook you pointed out is a good start, just need to make sure the weight is balanced so things don't slip. Plan for it now and you will need it sooner than you think.
FIRST, make sure you have sufficient rear weight to keep the wheels on the ground....chain the FEL down so it can't move, then try to lift it until the relief valve pops....if your rear end comes off the ground or gets extremely light, proceed NOW to get extra weight...loaded tires or something more back there.