Vyos 1.4.0, Kernel panic after enabling ipfix

[olofl]

Vyos version: 1.4.0
Environment: vyos on vmware

Configuration: 
[edit system flow-accounting]
vyos@vyos# show
+enable-egress
+interface wg0
+netflow {
+    server 1.2.3.4 {
+        port 4739
+    }
+    source-address "10.1.1.1"
+    version 10
+}

Hello, I enabled ipfix on vyos 1.4.0, and around 12 hours after, vyos crashed with kernel panic.
I was averaging around ~40 flows per second, at a 1:1 rate.
Syslog does not show any useful information about the crash. The solution was to reset the VM.

This is the only information I was able to grab, from the vmware console.

Edit: after reading the docs, I see it is recommended to use disable-imt parameter. Why is it not disabled by default?