Well, Take that last (ultimate) letter of each clue and totally ignore the grid. That will spell out a rather long and detailed challenge for crossword constructors. As a result we have all the solvers making these mini-crosswords.
What's the issue? 1A Beginning Place is EDEN (although in hindsight I probably shouldn't have said "beginning" place as we start the meta at 3D). 5A Australian lingo "afternoon" is shortened to ARVO. 6D. There is a raggae artist called TNEZ. Never heard of him? Well, he never heard of you either. I gave you titles to the songs so you can google him. 7A. There is a british company that make joysticks and game controllers called HORI, if you hadn't heard of it if you take the ring dance HORA and replace the A with an I you get HORA. 1D. Our planet is EA(R)TH remove the middle letter and you get EATH which is a scottish word for easy. 2D. Titular Bond villain. I don't need to explain Dr. No. 3D the answer is EVER and the rest of the clue explain the Meta. 4D. Just google this. It's NOZI.
The Event Horizon is an astronomical phenomenon around a massive body where light can not escape the pull of gravity. As such what occurs within the region where light can't escape will not be observable or in any way effect an on observer out side the area. This forms an observation/affect boundary.
Or do you mean what is the mechanism? If you start at 3D (where the clue tells you the meta starts but take left turn and the E and proceed to the left edge at square 6, then drop down to the bottom row and then procede in the only path left to us that doesn't cross our original path, the distorted path spells out E-V-E-(left turn)-N-T-(drop)-H-O-R-I-(turn up)-Z-O-N
Informal Australian for afternoon: "See you this ----"
6A
Reggae artist with songs "Have an Affair" and "Super Mario (So Easy)"... yeah, he's never heard of you either
7A
A manufacturer of video game peripherals which, if you change the last vowel from an I to and A becomes an Israeli ring dance
Verticali
1D
Our heartless planet is no difficulty in Scotland
2D
Titular Bond villain
3D
Eternally: (and here [and ---- after] we drop into our meta before many distortions along the way)
4D
--- Sibaya: The Season 18 runner-up of "Idols South Africa" (surely there's no need to Google that)... I think this may also be a manufacturer of nasal sprays....