PAGEMAP & migrating from Google Custom Search Site Restricted Json API to Search Vertex AI Search

Question

I understand Google Custom Search Site Restricted is being depreciated. We searched for results from specific domains of websites and used microdata, such as PAGEMAP to extract descriptions and images:

https://support.google.com/programmable-search/answer/1628213?hl=en

https://developers.google.com/custom-search/docs/structured_data

        if 'pagemap' in crawler_object and crawler_object['pagemap']:
            pagemap = crawler_object['pagemap']
            if 'metatags' in pagemap and pagemap['metatags']:
                metatags = pagemap['metatags']
                if 'xxxx' in metatags[0] and metatags[0]['xxxx'] and not "lookaside" in metatags[0]['xxx']:
                    thumbnail_url = metatags[0]['xxxx']
                elif 'xxxx' in metatags[0] and metatags[0]['xxxx'] and not "lookaside" in metatags[0]['xxxx']:
                    thumbnail_url = metatags[0]['xxxx']
            if not thumbnail_url and 'cse_thumbnail' in pagemap:
                if len(pagemap['cse_thumbnail']) and 'src' in pagemap['cse_thumbnail'][0]:
                    thumbnail_url = pagemap['cse_thumbnail'][0]['src']

As I migrate, is this data still available? And which do I choose?

Website data OR Structured/Unstructured data?

website data:

https://cloud.google.com/generative-ai-app-builder/docs/preview-search-results#web

Structured/Unstructured data: https://cloud.google.com/generative-ai-app-builder/docs/preview-search-results#structured-unstructured

Thanks in advance. your text