Logic Masters Deutschland e.V.

This is harder, but polished and more beautiful version of my previous puzzle. The even square wasn't naughty enough, so it got kicked out the box and turned into a litter killer. Some of the kropki dots have gone missing and a few of them run into safer locations where they can't be attacked so easily. "Harder" doesn't mean this one actually requires any hard logic, but the solution path is much narrower and you have to look at the right spot and ask the right question to make progress. The easier version of Naughty Secrets is available here.

Is it true that every 9 cell region without repeated digits must add to 45? Or conversely must every 45 sum region without repeated digits have 9 cells?

Rules

10-in-9 Variant

Place the digits 0-9 in the grid so that every row, column, and 3x3 box contains every digit exactly once. To enable this, there is a single Schrödinger cell (S-cell) in each row, column and box, containing two different digits.

Killer Cages

Digits in a cage cannot repeat and must sum to the total in the top left corner. If S-cell or multiple S-cells are inside a cage, both digits are summed as independent single digit numbers and neither digit can repeat anywhere else in the cage. E.g. S-cell with [1/2] counts as 1+2 = 3 towards the cage total and digits 1 or 2 can't appear elsewhere in the cage.

Little Killer Clue

The clue outside the grid gives the sum of the digits along the indicated diagonal. Digits may repeat on the diagonal if allowed by other rules. If S-cell or multiple S-cells are on the diagonal, they are summed as independent single digit numbers.

Kropki Dots

White dots join consecutive digits. Black dots join digits in a 1:2 ratio. Not all dots are given. If S-cell in connected with a dot, both digits must satisfy constraint separately.

Play this puzzle on CtC web app.

Example Notation

Image below shows an example of notation I use. You may find some other notation more useful, for example pen tool. Try it yourself.