er er er er

If you can't compress the files over some Hammer bug, maybe remaking the map would be better.

Man, I keep getting messages every single day about the huge map size. One day I’ll record a video explaining why I can’t compress the files…

umm, 1.6 GB?
the resolution of the textures could've been preserved with "Point Sample" than to scale them up to 4K resolution with "Nearest Neighbor", or alternatively scale them up to a smaller resolution (i.e. 256x256 / 512x512) while keeping point sample. that's more optimized and less space-eating compared to the method you're currently using.

i noticed that two big deltarune maps here uses exactly the same method i mentioned (though the card castle map uses 512x512), which they save space than this. you should do the same with the other maps you have, not just this one.

1.6 GIGABYTES???

Optimize your map.

for some reason the author packed 8 bit undertale textures in 4k resolution and now the addon's size is 1.5 GB

is there some virus?

BRO.I INSTALLED

erm what the flip

1.600GB