Logic Masters Deutschland e.V.

Previous Dutch Flat Mate Puzzles
This has been a weekly series since '18 Oct 23'. Here is a spreadsheet link for all the previous puzzles in the series, which also has a few teasers for upcoming constraints/guest setters in the series (subject to change).
This alternative link offers a limited LMD search for Dutch Flat Mates.

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To play the puzzle, please click the image:

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Puzzle Link: Click Here

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Initial Setter Difficulty: 3 / 5

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Normal Sudoku rules apply
Place the digits 1-9 so that they do not repeat in any row, column, or 3x3 box.

Dutch Flats
Every 5 in the grid must have a '1' directly above it or a '9' directly below it. It may have both, but it doesn't need both.

Internal Skyscrapers
Each number in the grid represents the height of a building. Taller buildings block the view of buildings of the same height or smaller. A digit on an arrow indicates how many buildings are visible when looking from that cell in the arrow's direction. The arrowed cell itself is not counted, and its height does not affect visibility along that direction.

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Hint to start

Pencilmarking the Box 4 clues should lead to a flurry of early digits, although the resolution of R4 will require far trickier consideration.

Next Step Hint

Several Dutch Flat Mates observations must come together at once for progress (more than just those listed here).
9 in Box 7 should be one of your early digits.
9 in Box 4 is also gettable very early to avoid a forced unhappy 5.
Then, wherever 9 is placed in C2, it has powerful consequences for Flat Mates.
You're on your own from here to actually place a digit, but 1s, 5s and 9s are the key to progress!
Please note that the R7C9 arrow isn't useful until the very end of the solve.

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Next Week
A collab with palpot, or a 'Flintpot' if you will. A draft that has likely waited over a year for its turn in the spotlight! It kept getting bumped when queueing the series, typically to accommodate the wonderful puzzles of guest setters, but it's always comforting to know you have a good draft in the bank. Whilst the puzzle was never DESERTED; it carries a LOW risk of being forgotten, a MEDIUM level of difficulty, and a HIGH chance of happy 5s!