Should i be worried about this line in server config?
[DynamicEV Thread/INFO] [Equivalent Exchange 3]: DynamicEV system initialized after 65142 ms
EE3 does some task there everytime server starts that takes over a minute.

Using version EquivalentExchange3-1.7.10-0.2.295

This issue has been closed for some time, but the serialization of values and the specification of custom values by end users has been drastically improved recently :)

If this happens EVERY time the server starts, shouldn't the result be cached in some file to reduce startup time?

It's in the list of things to do (serialize the results to disk with a hash of the modset) so that it's not genned again unless "triggered"

Not an issue - that's EE3 dynamically generating values for items. The more mods you have the longer it will take.

Should be closed with fe7afe1