The best option for embedding your service for client sites?

Question

JavaScript

Greetings!
I created a service similar to an online constructor, I want to offer interested companies the opportunity to embed it on their website. But here the main snag is how to do it in the most optimal way.
The service itself consists of a lot of JavaScript + css + some logic and php + a lot of heavy images.
What options do I see -
1. embedding via iframe,
from the pros: ease of embedding, the ability to quickly update scripts
from the minuses: a narrow channel and brakes with loading, difficulties with customizing the appearance for the client
2. place pictures + scripts and other with clients, leave only logic.
of the pros: fast loading, the ability to easily customize the appearance for the client
of the minuses: difficulties with installation, difficulties in updating new versions of the service
How would you do it? Maybe there is another way?

Answer 1

The worst ways have come up.
And the most correct and obvious was missed.
Installing a small code for clients on a site like any counter / service: metrica, adsense, etc.
If this is of course possible. Depends on what needs to be done on the client's site

Answer 2

I would choose the second method and add a PHP script to it, which will download everything you need from you and scatter it on the client as needed.