when it tries to spawn bases, or when it is spawning a base?
if the former then there's nothing that can be done about this until it's made into a coroutine. it's 100% reliant on your machine to be able to handle it
if the latter then CopyPaste should be configured to paste no more than 5 entities per batch
all other performance issues were fixed. 1. setting up the base once it's been spawned, and 2. when despawning the base. if you lag during these times then it's your machine. this is why it intentionally takes a very long time now to setup or despawn a base (to prevent performance issues)
number of bases on a map depends on several factors including your entity count, player count and machine
it really sounds like CopyPaste is configured wrong, your machine specs are not up to par, or you simply have too many plugins
"Amount Of Entities To Spawn Per Batch": 1,
"Amount Of Entities To Despawn Per Batch": 10,
this can cause issues if set too high