Welcome to the community. HE integrates with echo. You just need to, like you said, forget them in echo and connect them through HE. There is a skill for that and a .. I think .... native driver. (I'm not home to check on the driver) After you're migrated, you expose what you want to echo and you're good to go.
You'll need to reset your ge switches and they're a bear to deal with. I had 15 to migrate when I came from ST. Reset them and do a generic zwave exclude. If you get in the logs "unknow zwave device excluded" then you can join that one and move on. If you're on a C7, I'm unsure of the protocol for that as I have C4 hubs. I used this youtube video to reset the switches. It worked for me
There is a harmony integration. Search it out
Hue can connect with the bridge
and sengled connects directly to the hub.