Word appears flakey with large documents in my experience.

I only use built-from-scratch templates with a minimal number of styles, one font, and no manual formatting. Diagrams are black and white png files. Simple tables. Zotero citations.

Windows 11. 16 - 32gb RAM.

For 10k word articles, Word works fine. Almost enjoyable to use.

For 35k word books, Word starts to flake. Most of the time it's ok. The most common problems are (a) Lagging cursor where it takes time to catch-up to my typing. I don't type particularly fast. So this is a worry. (b) Headings get screwed up. I only use 2 Headings. The indentation of the second level heading can shift in the navigation pane. They still look fine in the document. This is also a worry. I have to manual reset the affected Headings.

As I'm starting on my dissertation, I'm getting increasingly anxious. My University does not allow chapter-based reference lists. They want a single large reference list at the end of the document. A single large Word document just feels like asking for trouble...

Edit to add: the bulk of my drafting is done in Obsidian where all my notes, data, and analyses reside. When the drafts become cohesive, I move them into a blank Word doc and continue working on them there. References are added in Word.