Currently, Localazy has some support for plurals as per documentation. The documentation explicitly says: “Localazy supports all plural types from the latest version of CLDR definition file.”
From my point of view, this is not true, as for example in Czech language there isn’t support for “many” type or in Russian there isn’t support for the “other” type (you can find the plural types in the CLDR Plural Rules). It seems that the common denominator for these unsupported types is that they are used for handling only decimal numbers.
Current Czech rules in the editor
CLDR Plural Rules for Czech
If you are going to support these types, then you would also need to update the documentation as only three Czech plural types are mentioned there (for example in the Plurals section of Flutter ARB format).