If I update my locale settings in Salesforce to Spain/Spanish/EUR, will currency and date formats update accordingly in Apsona and document merges?

Yes, if your Salesforce user locale settings (Language: Spanish, Locale: Spain, Currency: EUR) are updated, both currency and date formats should reflect accordingly across Salesforce and tools like Apsona. This includes UI views, exports, and dynamic document merges, provided the templates are configured to respect these formats.

Once set, tools like Apsona typically inherit these formatting rules. So if you see the currency appearing as EUR (€) but not the date format, it's likely a template-level limitation rather than a problem with your locale settings.