How to make different serializers for the same Ember.js model?

Question

Ember.js

Ember.js 2.7 pods
have the following
/pods
/pods/order/model.js
/pods/order/serializer.js
/pods/order/index/route.js
/pods/order/index/template.hbs
/pods/order/ edit/route.js
/pods/order/edit/template.hbs
/pods/order/new/route.js
/pods/order/new/template.hbs
router.js

this.route('order', { path: '/dashboard/order/' }, function(){
    this.route('new');
    this.route('edit', { path: '/:order_id/edit' });
  });

model.js

import DS from 'ember-data';

export default DS.Model.extend({
    customer: DS.belongsTo('customer',  {async: true}),
});

serializer.js

import RESTSerializer from 'ember-data/serializers/rest';
import DS from 'ember-data';

export default RESTSerializer.extend(DS.EmbeddedRecordsMixin, {
  attrs: {
    customer: {embedded: 'always'},
  }
});

How to make sure that there is no customer in the index route, and for example, there is already a customer in the edit route, api returns accordingly, for api / orders without customer, and for api / orders / 2 already with customer
Tried to put serialize.js in each folder(index, edit, new), but that doesn't work.
I hope I explained clearly.

Answer 1

I tried to put serialize.js in each folder (index, edit, new), but it doesn't work like that.

I didn't work much with RESTSerializer, but it definitely won't work that way.
Maybe it's easier not to insert the customer into the output for order, but to load it as needed (only in edit) with a separate request?
Why is this behavior even necessary?