The embed works perfectly fine, as on any HTML page... what are you looking for exactly?
I would like to ask the developers to create a webpage template, where we can insert the embed code only. The CMS will be used by different people, and it is important to have a simplified process where they can just take the embed code and paste it. We are not there yet, but im sure when it comes to the testing I will come up with a lot other questions. Good to know that I can ask you for help
You can use embedded Marketo forms on Episerver. It's possible to create a simple template or content block where you can just paste the embed code. I'd prefer content block because it's more versatile to use.
Embedded forms may be blocked by solutions like AdBlock (content from another site blocked) so it's not the best solution, but I agree that it's the easiest.