You can open the form page (ASPX-file) in the SharePoint Designer and add as many web part zones as you need.
Also, I'd recommend you truing Plumsail Forms Designer for creating a form with related items without coding. The software itself is not free but saves a lot of time so finally it will cost less than if you'd implement the same by yourself.
You can use your RESTful URL something like below:
/_api/web/lists/GetByTitle('<Display name of #List2>')/items?$select=Title,Country/ID,Country/Title&$expand=Country
Country: Lookup column in #List2 which is referencing data in #List1.
Country/ID and Country/Title: Gives the ID and Title for selected Item from #List1.
If you are ...
I don’t think there is any OOB solution to sort lookup column in modern list view.
You need to consider custom solutions with SPFx extension.
Migrating from JSLink to SharePoint Framework Extensions.
Can it be the case that someone has reduced the lookup threshold value for the farm to 8 (From larger number before?) If some inexperienced admin would run health test that might have been flagged up; he corrected it not knowing it will affect some of your sites?
Re: "a different farm administrator to me could still edit items, while I could not (despite us ...
I changed the List View Lookup Threshold to 12. The list now works again for everyone. I'm puzzled why it didn't work before, I've read some conflicting info on this - some things I've read explain that any value over 12 consumes more 'system resource' (SQL has to perform a join query - more info here). My item content type only had 9 lookup/person or ...