What is the largest possible Terraria player savefile?

What is the largest possible Terraria player savefile?
pointless dead discord: https://discord.com/invite/yJrCt9YFz5

Chapters:
00:00 Intro
00:49 Why we only need to focus on a few “variable-size” things in the save file
01:38 What are these “variable-size” datapoints that we need to maximize?
01:46 Part 1a: making the player name as long as possible
02:07 Part 1b: using as much space as possible with Chinese
02:33 Part 2: unlocking all the research
03:28 Part 3: recording two hundred spawnpoints
04:22 Part 4: the secret 59th and 60th inventory slots
05:01 Conclusion and outro

Icons from Freepik and inkubators via Flaticon

Music:
Terraria – Alternate Underground
Terraria – Morning Rain
Terraria – Town Night
Terraria – Aether

What is the largest possible Terraria player savefile?