While I can’t speak specifics related to zram configuration, I can say that the Alexa skill experience will be affected, especially in the Alexa app, if the performance on a given OH server is degraded.
The reason is that when you browse through your devices in the Alexa app, each device is generating a request to get its latest state from your OH server. If your server struggles to response in time, these devices will be determined as unresponsive on the Alexa side.
Tags are no longer supported in OH 3.x. So you should remove them. As far as the metadata configuration, it should be added with your existing metadata configuration and not separate.
Dimmer zwave_lights_lounge_table "Living Room Table" (gLoungeLights) { alexa="Light", channel="zwave:device:1234abc8:node7:switch_dimmer1" }