Hello,
There are many GUI frameworks (ExtJs, SmartClient, OpenUI5) which do not works in React way and they could be easily be integrated with JSX/TSX if their JSX expressions would return correct "element type" e.g.
const listGrid = <ListGrid/> ; // should be type of ListGrid or isc.IListgrid, not JSX.Element

My proposal would be to add new special type into global JSX namespace - ElementTypeProperty.

JSX.ElementTypeProperty

Given an element instance type, we need to produce a type that will be return type of that JSX element. We call this the element type.

The interface JSX.ElementTypeProperty defines this process.
It may have 0 properties, in which case element instance type will be element type.
Or 1 property, in which case the element type will be the type of that property type of element instance type.

Note: Intrinsic lookup is not affected by ElementTypeProperty.

Related: #13746