Pdf Generation Performance with PdfGenerator

I’m using successfully pdf_generator to generate multiple PDF or IMAGES files from HTML files/strings.
We need to increase performance and even with some Parallel functions help (ParallelStream and Flow), it’s limited due to xvfb headless display (On a Mac I couldn’t find xvfb-run that works).

Docs in https://github.com/gutschilla/elixir-pdf-generator says:

If you will be generating multiple PDFs simultaneously, or in rapid succession, you will need to configure xvfb-run to search for a free X server number, or set the server number explicitly. You can use the command_prefix to pass options to the xvfb-run command.

config :pdf_generator,
    command_prefix: ["xvfb-run", "-a"]

Does anyone tested on a Linux (In our case Docker / Alpine) and achived better performance?
Anyone tried other package?