I don't think that ECS does have much to do with the performance of your actor creation (nor does Lua or LÖVE). IIRC you are using a library from the T-Engine to achieve your OOP behavior and I'm pretty sure that's the bottleneck - or some other (fixable) inefficiencies in your code.
I haven't checked the time of my charcater creation but I'm sure it is pretty low and I'm generating characters with graphs to simulate the body, behavior trees, items, stats and so on. If you point me to the character creation methods I could take a look at them if you want to.
Also some stuff can take a while no matter how much you optimize it though 4 actors really shouldn't be a problem for any modern hardware.
tl;dr: OOP doesn't make code slow automagically. ECS doesn't make code fast automagically
Let's get some stuff done till saturday
