Get the Nela cracking trowel but you do have to take care of it especially around plugs as it can bend easily if you hit them hard, I have not used the ox but have heard good things about them so it is your choice.
Super trowels! I just can’t watch them getting destroyed by the skim! God knows what’s in it. No other product I came across is turning them so s**t. Decided to keep them only, mostly , for externals this year. See how it goes.