Your problem would be related to the rule you have on your lan that forces all traffic out this MGW_MAIN gateway.
How is suppose to get to your 10.41.0.0/30 on igb0 when the allow rule that allows traffic will force all its traffic out this MGW_MAIN gateway.
And your rule on your timenet_modem /30 network has your allowed source as your lan..
Your problem is not so much routing, but your firewall rules.
Rules are evaluated top down as traffic enters an interface.. First rule to trigger wins, no other rules are evaluated. So traffic trying to go to timenet from lan would be sent down the mgw_main gateway. Which not sure what that is from the info you provided. You need to put a rule above this rule that forces it out the gateway with no gateway set so pfsense can just use its routing table to get to the other network attached to pfsense.
Your traffic coming from your timenet network trying to go to lan woudln't go anywhere, because the source of the traffic would be from the timenet /30 not lan - your rule on timenet inteface says the source has to be lan net - which never going to be the case.
BTW - pfsense is not going to nat traffic between networks directly attached to it, unless you set it up to do so. It would only create nats for traffic going out what it considers a wan, ie has a gateway set on the interface.