Alright, I found a seed (version 1.12.2!) with EVERY biome within a 13,000 block radius of spawn (Spawn coords: 265 65 -1086). It sounds large, but it really is difficult to get those extremely rare biomes... so I've made it a priority to find them in one seed. It's extremely convenient if you're using a waypoint mod like myself.

You'll spawn in the ocean right beside a Seasonal Forest. It's sort of an island, there's a long chain of land and biomes northeast of it. I'll give the coordinates of the rarer biomes, if anyone wants anything else specific, try the biome finder (mine the ore in survival) or use /bop tpbiome <biomeid>. Some biome ids are one number off on the wiki so just experiment with it.

Origin Island: -11159 63 -9245 (seems like a large island)

Tropical Island: -7944 71 -11368 (also pretty large)

Ice Spikes: 8643 72 7600 (old biome and very small, but why not?)

Cherry Blossom 1: 7964 109 5940 (mountian right beside cherry blossom forest. cute view.)

Volcanic Island: 9444 131 7452 (Really large set of volcanic islands)

Flower Island: 10085 74 4047 (Medium sized island)

Lush Desert: 10988 63 -267 (Lush Desert beside a mesa and with a village nearby)

Overgrown Cliffs and Bamboo Forest: 10470 104 -2812 (Self explanatory, also I believe there's a rainforest biome nearby too. good find)

Mystic Grove: 3625 65 -6237 (Mystic Grove and marsh area.)

Ominous Woods and Cherry Blossom: 4290 64 -6428 (Another great find, something so dark by something so pure...)

Orchard: 3374 66 -3201 (An orchard,, forgot what's nearby.)

Sacred Springs: 4822 69 -1027 (Large sacred springs biome!! sooo glad i found this gem)

Land of Lakes: 1570 64 -1809 (Loveee this biome so had to include it, also its very large)

That's my list,, note that this might not be super convenient for the survival players unless you use tp/waypoints. Also because I didn't add very many village, temple, etc coordinates either, because although they're cool, I really just wanted to put this together because a builder like myself likes to build random houses in every biome. Or have access to all the biomes. If you would like to find those types of structures, do it yourself or use another seed. Anyway, I hope at least some of you like this seed!

Seed: 8240262212944608719