on Slippery which has a floor stepped mast the kicker most of the kicker loads are attached to the mast step. This means the mast is pushing down and the kicker is pulling up. I did have the ends of the cascade part of the kicker and the bottom of the 4:1 purchase part attached to the mast but both attempts suffered from chafe and finally gave up at bala. the only loads not coming off the mast step are the loads to the cleats which are marginally small.
Assuming I pull on 20kgs of kicker tension a 16:1 purchase has 320kgs of tension in the first line of the cascade, 160kgs in the second line and 80 in the third. that's 560kg plus a factor of safety for shock load for slamming, wind loading, gusts or nose dives or a combination of the lot.
therefore if you attach the whole lot to a single point as i have it should be capable of holding at least 2 tonnes. If you take the ends of the kicker to several points each will be sharing the load.
The fittings leading the kicker out to the side decks could be carrying 100 kg's each.