For a long time, Aternos will deny access to Spigot's configuration file.
This may be disabled due to the fact that some settings are too intrusive/dangerous.
However, Spigot's "Per-world Settings" will prove useful to optimization,
and it also has the settings that most performance plugins use.
Why not make use og these plugins? Some of Spigot's stuff override and hinder other
plugins' functionalities, like ClearLagg's 'mob-range' and 'chunk-limiter'(Spigot can do this!).
Spigot even has optimization features no other plugins can offer...
This is why I recommend that users have partial access to Spigot's settings so that users can make better use of the limited resources.