I think it would be really great if we can customize the tool-tips for Qlik Sense in general but Maps in particular. The maps would be so much more useful if we can add custom tool-tip using expression builder. We have used QlikMaps which is a third party extension for Qlik, the only thing the extension does well is ability to create tool-tip. We can create formatted HTNL tables etc. as tool-tip.
Even for other objects like KPI's and Bar charts the custom tool-tip can be really helpful.