It's not the turbo that is wears the worst by driving cold, it's the engine. turbo shaft spins on a layer of oil and impeller bleds aren't touching, so there is practically no wear. Thick oil will impose more drag on shaft, making it spool slower but it won't wear the turbo.
Arguably, by driving on boost @ low revs, engine will heat up sooner due to greater heat buildup.
Thank you for your time,