Yes and no.
The height map from Gaea has an intrinsic limit on the amount of detail.
Say your height map is 8k and your terrain-size is also 8k then your heightmap resolution is 1m/pixel and is the limit of detail you can expect from the heightmap itself (Niquist frequency limit).
By default TG adds procedural detail to imported heightfields. Double-click on your heightfield shader node and go to the last tab called "Fractal Detail".
When disabling fractal detail and rendering the terrain without any other shaders than the default 'base colours' you will see the detail your heightfield has to offer.
When enabling fractal detail you will add procedural noise to your height field and then, yes then you have what you are looking for, but also with fractal noise there are limits to the amount of detail.
The fractal detail of the heightfield shader shows no scale options, so I don't know what the lowest scale is it can go down to.
For the powerfractal you can go down to tenths or even hundreths of a millimeter. All depending on how close you are to the surface and the micropoly detail as well.
The micropoly detail can be seen as screendependent, not scene dependent. The closer you are to the procedural terrain and with micropoly detail constant, the smaller the polygons will become in absolute size.
In a scene-dependent way you would have your 8k terrain being split into a certain number of polys and that's it.
