Cloud Hybrid Search leverage Azure AD Proxy to access on-premises content

We recently setup Cloud Hybrid Search for our on-premises SP2013. The Cloud SSA is able to send search index to the cloud and our SPO search center is able to return the result from on-premises content by using "IsExternalContent:true". When we looked the result from on-premises, the result actually shows the short name format like "https://itweb/sites/site1/aaa.doc" since we crawl the on-premise web application using https://itweb format because it's default zone. On the othe hand, we setup a Azure AD Proxy to bridge the user to on-premises content using https://itweb.contoso.com and the URL like https://itweb.contoso.com/sites/site1/aaa.doc is able to get through our on-premises content https://itweb/sites/site1/aaa.doc. My question is how to make search result shows something like https://itweb.contoso.com/sites/site1/aaa.doc instead of short name? I know Display hybrid federated search results in SharePoint Online at Configure hybrid federated search from SharePoint Online to SharePoint Server 2013 - roadmap mentioned to create a result source and specify "Remote Service URL" to external url of on-premises sharepoint server. However that's for "hybrid federal search" not for "cloud hybrid search" which allows user to have unified the result from both SPO and on-premises without showing any search verticals. We have done the following approaches:

1. For those internal web application like https://itweb, we extend it to https://itweb.contoso.com and then crawl https://itweb.contoso.com in Cloud SSA. I think this approach is kind violate the SP crawl guildance that it's best to crawl a default zone. The reason why we consider this way is because once we setup correct Azure AD Proxy to use https://itweb.contoso.com, with extended web application being crawled, the result will be accessed both users no matter if they have VPN or not.
2. Customize the search display template and replace the https://itweb url to use https://itweb.contoso.com if the result's IsExternalContent is true in search result.

We actually implemented above two approaches and it seems they are working, but would like to see

• If above approaches are recommended
• if there are better solutions out there. 

Thanks