I know your recourses are limited but try to make the servers 24/7.
A tip for that not have it online all the time have the plugins and mods online then when ppl join it starts after like 30 sec.
And ik afternos is supposed to be free but I would gladly spend 30 bucks for an easier domain with less server lag.
Then you could focus on more memory for the aternos community 
