Loudness levels and workflow

I use Ableton but I own Cubase too. I have a mastering question. I render my tracks in Ableton and put those into seperate audio files each track… synth bass, drums, melody etc have the focusrite FAST compressor, eq and limiter on them. I then send them over to Wavelab as an audio montage which I saw in one of the workflow videos and set the loudness to 16. After applying all the tracks are at the same level and I then use ozone 10 to master them. I have started adding vocals to the tracks but when I pass them through ozone 10 they seem to get louder again. So should I use the Ozone plug in before the audio montage stage or maybe there is a better tool with presets in wavelab to omit the need for Ozone. I have moved away from a Magix pro product due to cost and am discovering Wavelab now. Help would be appreciated for this newbie as I am sure there are hidden gems within the software. Apologies if it is a dumb question.