**Feature Request: Support conditional currency symbol positioning (prefix vs suffix)**

[kleostouraiti]

Problem
Superset currently only allows a single static prefix or suffix setting for number formatting. This doesn't accommodate the fact that different currencies follow different conventions:

• £ and $ are displayed before the number (e.g. £724,149)
• € is typically displayed after the number (e.g. 724,149 €)

For multi-currency platforms serving users across different countries, this means it's impossible to format all currencies correctly with the current configuration options.

Proposed Solution
Allow currency symbol positioning (prefix vs suffix) to be configured per currency, rather than as a single global setting. Ideally this could be driven by a currency code (e.g. GBP, USD, EUR) with sensible defaults for common currencies, while still allowing manual override.

Impact
Without this, either £/$ display incorrectly as a suffix, or € displays incorrectly as a prefix — both of which look unprofessional in client-facing dashboards.

Workaround
We have implemented a local fix for this but it requires patching Superset's source code directly, which is difficult to maintain across version upgrades.

Contribution
We are planning to raise a PR with our implementation of this fix, including unit tests, and would welcome guidance from maintainers on the best approach before doing so.