Q: let's say you want to tie the last 8th note of a bar to the first 8th note of the next bar (and the next bar is the first ending of a repetition). how could you indicate you want that last 8th note to be tied to the first 8th note of the 2nd ending bar as well?
A: make a tie at the beginning of the 2nd ending, coming from the left, not really connected to anything