I would highly recommend you create a DNS Alias that you setup outside of your Solarwinds HA which in turn points to the HA DNS Name. That way you can control the re-direct later on if required such as putting traps into a dedicated log server etc.
Both NetFlow and SNMP Traps should be configurable to a hostname, but it might depend on your equipment.
We have 10x HA pairs setup but don't like to rely on DNS for network devices as its outside of our control (and a lot don't support hostname trapping etc).
For our setup we have created HA pairs using dummy virtual hostnames that do not actually exist and a dns server that doesn't exist and is non-routable.
We have all of our HA pairs built and we use external load-balancers in front of the setup (with source address translation turned off) to forward syslog, traps and netflow across all of our poller pairs. that way we dont have to rely on DNS to receive incoming traps. As long as you trap to matching pairs its all good, even with multiple load balancers across different geographical regions because the Standby HA poller just drops any incoming messages, so no duplicates.
Probably not the most simple setup but it means we dont have to use any DNS and we can have a consistent config across our entire estate for Syslog, trap and netflow destinations.
There are at least three options available to you. Probably many more depending how creative you get.