Send timeouts per producer, not per Connection. Possible ?

Hi
I have an application with different Messageproducers which all send JMS
messages to the same Broker. I am using failover protocol. I use different
producers from different Sessions from different Connections. I need a
timeout function so the "sends" don't hang. This i set in the URI timeout
option for the different connections.
As i need DIFFERENT timeouts for different Producers, so I thought easy, I
setup different connections the differen Sessions and so i get different
Producers.
My problem is that as soon as i stop the Broker all sends from my
application get a timeout, but the timeout is always the one i set on the
FIRST connection i started. This kind of defeats the purpose of having
different timeouts. My question are now, is this a known bug / feature i do
not understand ? How can i achive different timeouts for different producers
? Is there an option to specify the timeout not as part if the URI on the
connection but on the messageptoducer / and-or per send call ?

I am using activem1 5.6, ready to upgrade to 5.7 / 5.8 if needed.

Thank you for any input.

mike