Anyone install aftermarket amp in EPS/Ind system?

[Lazardm3]

I couldn't find much in a search about this topic.

Has anyone re-coded EPS to hifi and amplified all stock speakers with say a multi chanel jl amp?

I'm curious about
- how many channels of balanced outputs are you left with after recode
- would I require new passive x-overs for the front stage or would I be needing to separately amplify tweets mids and woofers? As that would be 6 channels there, how do you set up rear stage. Would the stock hi fi outputs provide speaker outs to power the rear fill or would I need another multi ch amp to drive those?
- Does this recoding provide a pure flat signal free of eq and silly speed-adjusted volume eq?
- I read somewhere that the speaker outputs just require a speaker wire/rca cable and I would be good to go direct to amp(s). Are any harnesses required?
- Will there be any improvement in sound quality?

I'd likely add a processor into the chain as I'd like to also add another music source (streaming)

I read somewhere this is a preferred approach but don't really see much by way of install or info on the approach.

[nycplumber]

Anyone else? I have EPS and I would love to get 20% more sound