LR atties should be fine, but you'll have to charge more often...they are the same type A atty, and many people do use them, understanding that the battery life will suffer a bit. No mention of safety issues, though.
But this is a really tiny battery. 1.8ohms at 3.7v is 2.055 amps.
If the C rating on a battery is the same the larger battery can safely carry a larger amp load. I have not seen the C Rating on the various sizes of eGo C batteries but I did see a post there someone said one of the sizes of twist can handle 2.2 amps.
Some batteries can handle 10C while others li batteries are as low as 1.5C. A 500mah battery has to have twice the C rating to support the same amps as a 1000mah battery.
What that means is the 90mah has to be twice as good at supporting amps as the 180mah batteries I have tried this with. Maybe the batteries have double the c rating, I don't know.