Reading node js doc. They seems to be conservative in the default limit values for http body size and parameters quantity: 

<https://github.com/expressjs/body-parser#parameterlimit>

I've found you can extend it and this seems to be a proved solution: 

var bodyParser = require('body-parser');

app.use(bodyParser.urlencoded({
 parameterLimit: 100000,
 limit: '50mb',
 extended: true
 }));

However, two questions remain:

1. Why the default values are so conservative?
2. Why expanding the limit to 50mb is a good idea?

I know the answers depend on the application the solution is applied, but I would appreciate a more general approach oriented answer to understand better the problem.