So, I’ve recently managed to find a pretty interesting Hf based illegal connection involving the V1 chest plate and a metru foot, and it’s fairly stable too!
Now here’s the thing with this, while it is quite a stable connection do such it is not perfect, there is some looseness and if you plan to do some form of atop-motion/similar with this moc do expect it to fall off after being handled... roughly, if not secured through use of like an elastic band or some-such.
But, as said before it is a stable connection, and it won’t fall off unless you really fiddle with it’s connected piece or try to pick up the moc by this connection.
Some chests also will together better than others, such as with the Bulk one, which is the best connection I’ve found yet. And (as you can see below) this is not faked and can be supported by just the metru foot (it can also carry a good amount of added weight but definitely not a full, Toa sized moc).