Significantly slower indexing process since upgrade from 1.3.8 to 1.4.2

[hostep]

Hi guys

I'm trying to upgrade this module from version 1.3.8 to 1.4.2 (see changes)

But we are noticing an extremely slower reindex of the catalogsearch_fulltext indexer.
With version 1.3.8, the full reindex time was 3 minutes 59 seconds, but with version 1.4.2 it slowed down to 17 minutes 14 seconds.

I can restore the speed by disabling the "Use in Layered Navigation" of the custom entity product attribute. But we need that to stay enabled, otherwise no products show up when we visit the custom entity page on the frontend. Unless there is another way we can configure the attribute to keep that working?

We have one custom entity type and it has 3849 options. And we have 40322 products, 2 websites each containing one storeview.
Our catalog_product_entity_text database table has 231257 rows (I'm assuming the problem lies here as we got a lot of rows added to this table due to the upgrade...).

If you want me to debug / profile something, let me know what code exactly.

Thanks!