I don't think you're necessarily being lowballed. 0.1% is a reasonable number for a hands-on engineer in series A. Keep in mind that startups typically have maybe 20% of their equity allocated as the pool for stock option grants, and they guard that very closely. They need to reserve possibly multiple % for early executive hires such as VP of engineering or head of sales as they grow.
Also don't buy BS like "they say this grant could be worth $1m if startup is valued at $1b". Not only is there a small chance of them ever getting to a $1B valuation, you would mostly likely be diluted between now and then by additional funding rounds.
Also don't buy BS like "they say this grant could be worth $1m if startup is valued at $1b". Not only is there a small chance of them ever getting to a $1B valuation, you would mostly likely be diluted between now and then by additional funding rounds.