product or file edit?
 

what is better for performance? use a product with phrases, plugins, etc or make some file edits?

Save yourself from having to edit files every time you upgrade, use plugins :).

I was thinking that, but I prefer to spend a few minutes more editing files and have a better performance (in case that plugins slow down the forum)

I myself would like to know the answer to that, regardless of which one is better.

These two threads might interest you:
https://vborg.vbsupport.ru/showthread.php?t=104657
https://vborg.vbsupport.ru/showthread.php?t=137086

There is obviously going to be a greater impact (Although insignificant) on performance when using plugins over actual edits to a file; though this can be avoided by not using large amounts of code in plugins - or including a file (as seen in the first link) that contains the code being executed, rather than having it executed directly from the plugin.

It would be margingly better to store the code in the files, but signifacntly more work.

You're not going to see a difference in many cases.