[GNC] How to Handle Managed Securities Accounts in GnuCash

[rsbrux]

I have a couple of managed securities accounts which typically have a lot of
transactions involving switching in and out of proprietary ETFs for which
public quotes are not readily available.
I am tired of trying to keep track of all of these transactions in GnuCash.
I would be grateful for any suggestions as to handle these accounts with
less (manual) effort.