I noticed that I need to stop holding shift to apply mortar. I like holding shift while walking backwards and placing blocks below so that I don't pass the threshold of the block I am actually standing on. It doesn't seem like there's any added difficulty gained without this feature; just an extra step for placing each block the way I tend to do.
I don't know. Keep up the good work though. I was extatic to see all the recent updates, and I look forward to extensively playing the rest of your work. Cheers!