'Gestalt' by Group Theory -- Fog of War Sudoku

Full rules and Setter credits below:

Gestalt
by Group Theory
Normal sudoku rules apply: Place the digits 1-9 in every row, column and box exactly once each. Additionally the grid is partially covered in fog. Placing correct digits will clear the fog from surrounding cells, possibly revealing more clues.

Cells separated by the black dot are in a 1:2 ratio. Cells separated by the X sum to 10. Cells separated by the V sum to 5. Not all dots, X's or V's are necessarily given.

Remote sums: The digit X in the cage points to a second digit Y located X cells away vertically or horizontally. The number in the top left corner of the cage indicates the sum of X+Y.

Box Indexing: A purple shaded cell is a box indexer. If a cell in position X of a box is shaded, the digit in that cell indexes the position of the digit X within the same box. I.e. if a cell in position 3 in shaded, and the 3 is in position 5, then 5 must go in position 3.

Outside Clues:
X-sums: The 14 clue outside the grid shows the sum of the first X digits from that direction, where X is the first of those digits.
Skyscraper: Consider each digit in the grid as a building of that height. The 4 clue outside the grid gives the number of buildings that can be seen from that direction, with larger buildings hiding smaller ones.

Line Clues:
Lines are marked in the grid by the abbreviations given below. Lines may cross each other but may not branch. Digits may repeat on lines (except the thermometer and Nabner) if allowed by other rules.

German Whisper (GW) Digits along the green line must differ by at least 5.
Entropic (ENT) Every set of 3 consecutive digits on the peach line needs to include one high (789) one middle (456) and one low (123) digit.
The digits along the arrow (AR) sum to the digit in the attached circle.
Region Sum Line (RSL) Digits along the blue line sum to the same value in each 3x3 box the line passes through.
Between Line (BTN) Digits on the purple between line must be between the digits in the two circles at either end.
Thermometer (THM) Digits along the red thermometer must strictly increase from the bulb end to the tip. The thermometer has exactly one tip.
Nabner (NAB) Digits may not repeat along the gold line and no pair of digits anywhere on the line can be consecutive.
Double Arrow (DAR) The sum of the digits on the line must equal the sum of the digits in both attached circles.

Setters: 99%Sneaky, Lake, Kafkapharnaum, 3good5you, I Love Sleeping, Nell Gwyn, Dorlir, Sayori, Marty Sears, ThePedallingPianist, Crusader175, Ratfinkz, heliopolix, Sandra & Nala, AnalyticalNinja

[lake]

Thank you for solving! That was really enjoyable to watch :)

[michaelmatter]

Thanks for the wonderful solve, what a great Christmas gift! 🧡

I agree that corner marks don't look amazing and removing them makes the grid look so nice. (Cheers from 99%Sneaky)