Concecutive strings, looking for tester + has this been done

[Thorsby]

I am looking for someone to test this puzzle. 4 star difficulty I think. Also I am curious if this ruleset, or something similar has been done before.

Rules: 

Normal sudoku rules apply.

A number in a grey cell is X, and is part of a string of numbers that is exactly X cells long, not longer or shorter. Each number in the string is consecutive with any number next to it in the string.

The string of numbers is in a straight line, and can be either horizontal or vertical. 

A string consisting of just one number is valid.

All possible grey cells are given.  

Example:


The puzzle:


Solve in penpa

If you can solve this, post me the answer. Also let me know if the rules are unclear or could be phrased better.

[CJK]

Is a cell grey, if the longer possible string (in both directions) has the length X, or is it grey, if one of these two directions has a string of length exactly X?
E. g.: If we have something like this:

3 4 5
8 1 9
7 2 6

Should the 1 be grey or not?

[Thorsby]

Is a cell grey, if the longer possible string (in both directions) has the length X, or is it grey, if one of these two directions has a string of length exactly X?
E. g.: If we have something like this:

3 4 5
8 1 9
7 2 6

Should the 1 be grey or not?

One of the directions. The 1 should be grey.

[Thorsby]

Is this a clearer phrasing of the rules?:

Normal sudoku rules apply.

A number in a grey cell X, is part of a string of consecutive numbers that is X cells long. The string must be in a straight line going either horizontally or vertically. Each number in the string must be consecutive with the next number in the string.

A string of consecutive numbers that is just a subset of a longer string of consecutive numbers going in the same direction does not create a grey cell.

A string consisting of just one number is valid.

All possible grey cells are given.

[Thorsby]

The puzzle has been tested. I'll probably put it up tomorrow.