Three-away Sudoku puzzle

In a possibly inevitable next move (although in this case, I think, a probable conclusion to the theme rather than a stepping stone!) I thought I’d try out Three-away Sudoku, where black markers indicate all neighbouring squares with a difference of 3.  With a 9×9 puzzle this still allows somewhat interesting 1-4-7, 2-5-8 and 3-6-9 chains to be used, although of course as you decrease the quantity of numbers that can fit in a chain so you start to lose the longer connected chains which I personally find so interesting.

Other than the three-away markers this is a regular 9×9 Sudoku puzzle, so just place 1 to 9 into each row, column and 3×3 box.  Squares with a thick black bar between have a difference of 3 (e.g. 1&4), and those without a thick black bar between have a difference which is not 3.

An idea I have in mind to try next is to mix consecutive and two-away Sudoku in the same grid – I think any other combinations would be too confusing to play, although I suppose you could insert small numbers between squares to show selected differences which might make an interesting but possibly too mechanical variant.  For me, I don’t want to have to stop and think about the rules I’m applying – in a good puzzle they should become intuitive really quickly (even if, in some cases, they are a little complex to learn they must become second nature for the puzzle to succeed – or so I find!).

Good luck!