The cabinet scraper will scrape soft polish off . You may mark the top and a little more sanding could be needed.
Steel wool and Blackwood can be a bad mix. So can scrapers and Blackwood usually its if any water gets near the job . The Blackwood reacts and iron oxide stains can occur.
I'm only on my first can of Osmo . There seems there is a lot of rules that you have to stick to .
not sure about shellac and Osmo.
I have been playing with oil based sanding sealer and Osmo and that seems to work. That's good because You cant seem to fill grain with Osmo alone. So a sanding sealer first and finish with Osmo table of mine is almost finished. It'll need a wax to complete it .
Yep dinner sounds good . Just fly me up :).
Hope it works out and do post pictures.