Custom ColumnTypeScanType

Is there a way to change the default scanType for a pgType?
for example I have a custom type for sql date types and it has implemented Scan and Value methods, but when I have a dynamic query and pass map[string]any as gorm Scan input, it still uses time.Time{} for date types.
And also for database numeric type it is using float64 which in some cases the number overflows.

Start by tracing how PostgreSQL date and numeric types choose their default scan types when a dynamic query is scanned into map[string]any. Compare that path with custom Scan and Value implementations, then determine whether configurable scan types can cover both date and numeric values without overflow; done means the requested behavior is specified and covered by tests.

Written by the indexing model from the issue text.