I need to use another libraries, like for example Google maps.
Would it be possible to use them in Dash in a logical and simple way or by contrast would it be better use Javascript with plotly and, also, another JS libraries.
The client who I am working needs a big customization and this is a PoC. Do you recommend changing to JS for the main APP.
Is it hard to answer your question without more details on the project. Which libraries do you actually need?
In general, it is relatively straightforward to port a JS lib if a react wrapper already exists. However, if all the libraries you need are only in JS (and you do not need any python libs), you might be better off with pure JS.
Either way, it might be a lot of work for a PoC, if you need to do many customizations.