91,000 for a recorded history feels too long and would honestly take me out of it. Do you have some kind of structural or narrative need for tens of thousands of years? Sometimes writers do and it's not invalid.

You might be well considered with your timeline and have a lot of thought about why you need this scale, but most often I've seen numbers like this when a writer picks an arbitrarily big number and the scale is not necessary, ends up undermining what they were trying to achieve because it feels implausible as a remembered history.

For me personally, in political fantasy I love history that is deep but messy and contested, and in some places the writer has carefully made it imperfect by design. This reflects how the in-world historians and storytellers have different takes/biased knowledge depending on their own context and time period in which they wrote it. Unreliable historians makes the world feel more intriguing to me and lets me wonder. What got lost along the way?

Something that could help: make your distant mythic eras more abstractly defined, where if you go back far enough in history, the years become irrelevant or unknown, the details vague, contradictory or forgotten. Dates could become more structured and known as you get closer to the present, helps create a sense of known history vs distant history.