I enjoy the mod very much, but when I playin creative if I make something using too many 'chiseled' blocks it corrupts the chunks it is in, freezing my character if within the chunk and not loading the chunk correctly. I am unsure of the exact problem that is causing the issue. For more information I do use the blueprints quite a lot as it helps speed the building process up and I have the Corrupted file and the back-up file of a world I have been working on, I have lost a few worlds and may hours to this.

I'm thinking this might be because of the high nbt size

Unable to reproduce, can you send both worlds and the mod list?

SW Corrupted.zip
SW Working Backup.zip
mods.zip

Here are the corrupted and working worlds and my mods.

I was able to load the chunks after removing immersive portals

This issue seems to not be present in immersive portals 0.9 (your version is 0.8)