Recursion takes too much memory compared to earlier versions (1.4.6 or earlier)

Digging further, the module collects same entity multiple times so looks like it is cyclic until it runs out of memory or times out.

 array:2 [▼
  0 => "taxonomy_term"
  1 => "1336"
]
 array:2 [▼
  0 => "taxonomy_term"
  1 => "439"
]
 array:2 [▼
  0 => "taxonomy_term"
  1 => "1336"
]
 array:2 [▼
  0 => "taxonomy_term"
  1 => "439"
]
 array:2 [▼
  0 => "taxonomy_term"
  1 => "1336"
]
 array:2 [▼
  0 => "taxonomy_term"
  1 => "439"
]
 array:2 [▼
  0 => "taxonomy_term"
  1 => "1336"
]
 array:2 [▼
  0 => "taxonomy_term"
  1 => "439"
]

After further investigation I found versions 1.4.7+ are unusable for complex websites with a lot of references.

The issues discovered:

• Even if taxonomy terms are UNselected in config, the module still exports taxonomies
• Taxonomies go into infinite loop, because of $this->exporter->doExportToArray($entity->get('parent')->entity) in Drupal\single_content_sync\Plugin\SingleContentSyncBaseFieldsProcessor\TaxonomyTerm::exportBaseValues()
• Instead of single content it is now exports all the content linked with no mechanism to stop it so it can result in hundreds of nodes instead of one.

that's not a critical issue, it's easy to fix, expect a new patch in a few minutes

well I don't know what is your exact structure, so it's hard to test it for me as I can't reproduce it. In any case, I provided a MR that might improve the export. Do you export node with a taxonomy reference or you export a taxonomy entity itself? Please provide mode details of your content structure, so I can replicate it at least

Nope, getting

The website encountered an unexpected error. Try again later.

Error: Xdebug has detected a possible infinite loop, and aborted your script with a stack depth of '512' frames in Drupal\Core\TypedData\DataDefinition->getDataType() (line 54 of core/lib/Drupal/Core/TypedData/DataDefinition.php).

I asked you a few questions and received 0 answers, can you please provide any information about your content structure. If the issue is not reproducible out of the box, this cannot be critical

Thanks @nginex. Production data is too complex to export.
Let me setup clear instance and try to replicate it.
From what I investigated, entities that are referenced in text fields are being exported as well (both taxonomies and nodes).

Correct, that feature did not exist in 1.4.6. Probably it makes sense to change the logic of export there. Let me update the patch and try to optimize that moment (instead of exporting full entity I will only export stub version of it)

I provided a few new options of exporting for menu links of content and embedded links from formatted text. By default it will be Stub mode instead of Full one. Also it's possible to select None.

Let me know if new patch works for you. Don't forget to run drush updb.