Dummynet blocks NAT traffic in floating "pass out" rule

[leeyc0]

I have a firewall with multiple interfaces, which required NAT to access the internet. I'd like to limit my aggregate internet traffic to 30Mbit/s, so I configured a dummynet limiter as such. To simplify the configuration, I configured a "pass out quick on wan" rule in the "Floating" tab, and visualized below:

 Internet
    ^
    |
|dummynet|
    ^
    |
-----------
| pfsense |
-----------
  |      |
|LAN1| |LAN2|

But I found that after I configured such rule and applied dummynet, NAT traffic are blocked. At last I have to change it to "pass in" rule, but it had a side effect that LAN1<->LAN2 traffic is limited too without configuring some extra rules before the dummynet rule….

Is it a bug or misconfiguration?