if not that, you can potentially use a property value converter for RTE, and process the outputed object, and move the anchor to the href, or whatever kind of output you need basically:
https://docs.umbraco.com/umbraco-cms/customize-the-backoffice/property-editors/property-value-converters
have not tried it with RTE fields specifically, but I think this would be the extension point to use if you only want to change what is outputted towards the content delivery API
More specifically, you can you can use
IDeliveryApiPropertyValueConverter