1% + market salary at an A-round funded company is an extremely good deal for an engineering role.
By all means, you should try to negotiate for more, but as the first employee at one startup and the third at another I was never given more than about .5% initially, with additional grants later on as reward for high performance and to help offset some dilution in later rounds.
Your risk profile may be lower than theirs, but I would take 1% as a signal that they really really really want you. I can guarantee they are not going to be giving employees 5-10 anywhere near 1%.