It is possible to specify more than a single bounce in a packet's header, but it seems unlikely that you would ever need to bounce a packet more than once or twice. If you are planning a system where packets will be routinely bounced off of many intermediaries, then we strongly recommend that you make sure there is no simpler solution. Such a system could be a pretty inefficient way to transfer data.
In fact, radio performance suffers dramatically whenever packets are forwarded (by either a relay or by bouncing packets off of an intermediate radio). Although this feature will help you reach radios that you could not communicate with otherwise, do not expect the same sort of throughput you would normally get between radios.
Suppose radio 63:1 needs to send a message to 64:2. Instead of targeting an imaginary radio 63:2 and having a relay bounce the message to 64:2, the user hardware attached to 63:1 would format the message's header with the bounce list 63:1