Westwater Prod.Thingamabobber Strike Indicator

How much weight can a 1/2" thingamabobber suspend? What's the limit, that you've found? Please be specific. Thank you.

Do you just stick the regular loop through and peg it?

If you want to add to the line and already have flies tied on, do you need to cut them off and string this on first and re-tie?