As an investor who invests at the Seed to Series A stage, I can tell you that a non-participating 1x liquidation preference is standard. I would refuse to invest in any deals that didn't include it, but won't be asking for anything more.

I think it's a pretty fair term. It prevents investors getting screwed by a sale for less than the round valuation, which could look quite attractive to a founder who could get their first million, screwing their investors in the process.