Hello,
I think it’s a bug :
In Brush parameters > texture > pattern > options : the preview of the texture at the top of the window is not updated when the scale slider is moved.
In my opinion, the 100% contrast with the aliased borders is alright. Since screentones are typically used to quickly create texture or shading, I don’t think aliased borders would appear out-of-place.
I haven’t had a chance to use the new halftones filter yet, so I don’t have any thoughts there. I’ll try to put them into my next Inktober drawing and report back!
I just tried out the half-tone filter, and the 45 degree default feels and looks normal to me. Plus, if it’s important for CMYK separation, then it’s probably for the best that it stay default like that. Wouldn’t want any accidents while printing after all!