Hopefully, someone from 1471 will post. Their members are active on the forum and they built an excellent chain bar this year. You can see some of it if you search the thread about their robot.
I’m pretty sure the Lynfield team also used rope attached at the ends as a backup in case the chain broke. I think they also cable tied the chain links together when they changed from tank tread → chain, where possible (so the main lengths, jut not at the bits that went on the sprockets). I might be mistaken about that though. It was a while back
I haven’t used a chain bar in sack attack, but it seems like a very effective lift for the game.
-light
-reaches the high goal
-a lot of reach distance over the trough
-can be made to go under the trough
1:7 and 1:9 seem to be the most common gear ratios. Most of the chainbars I have seen tend to be quick and efficient rather than high capacity.