No Lite! about it. I've twice unsubbed from YTP because they started showing me ads. Never again.
I've never seen an ad logged in to Premium. Content creators do sometimes insert sponsor segments directly into the video, but YTP offers a skip feature that works fairly well.
They do sneak it in when a blog etc plays an embedded YT video. It treats that as non-signed-in, you have to stop playing and continue on YT to avoid ads in that scenario.