Logic Masters Deutschland e.V.

This is a puzzle that I created for mathpesto's birthday, which they encouraged me to share with all of you. Ratings, comments, and feedback are much appreciated! Please feel free to reach out to me on Discord if you have any comments or questions. Please also feel free to try my other puzzles here.

This puzzle uses a variant called Landvermessung (Land Survey or Land Measurement) which is not very common. If you have not solved this type of puzzle before and would like to familiarize yourself with the rules, here is a playable example without the other variants that are in the main puzzle (standard rules are in the link): https://tinyurl.com/28adrvpg

Without further ado, here is the main puzzle!

Rules:

• Each of the six letters in the grid represents a different digit from 1 to 9. Within the grid, there are eight regions containing these six digits, each of which is a group of six orthogonally connected cells that is entirely shaded or unshaded; regions with the same shading may not touch orthogonally. Digits may not repeat in rows or columns, or within regions.
• Clues in circles are both quadruples clues and land measurement clues (the size of the circles is aesthetic only). Rules for these clues are as follows:
• Land measurement: Shade some cells such that no closed loops exist among the shaded cells and no 2x2 area is shaded. For circled clues, the sum of the associated digits indicates the number of cells in the shortest path of shaded cells that visits all of those directly touched by the clue. Circled clues behave this way whether the clues are in black or red text.
• Quadruples: For clues in black text, the digits represented by the letter(s) in the clue must appear at least once in the surrounding 2x2 area; if a letter appears twice in such clues, the associated digit must appear twice. For clues in red text, these digits must NOT appear in the surrounding 2x2 area.

Penpa+: https://tinyurl.com/2ypkbvcu