Where might I go from here?

[rbnvgl]

One year ago, I asked for help with tectonics on this board (here). Thanks to the answers in thread, I kinda tossed the idea of tectonics overboard and just started working, I have enough inworld reasons to explain away strange landforms anyway. I picked a regional map for starters and just painted a atlas style topography and a lot of rivers. The image below shows where I am now. It was quite a lot of work to get there.

Bildschirmfoto 2022-02-09 um 18.59.10.png

I really love the idea of having a map this detailed, but painting a semi-realistic topography by hand is a) just impossible and b) even approaching it with my humble methods ultimately too time consuming.
The thing is also, I have six part maps of this size still to do, to get my main continent together. And I really, really want to get to climate mapping/city names/borders/roads/worldbuilding this year...

So I`m looking for shortcuts now, perhaps someone can point me in the right direction. I read some things about heightmaps and this wilbur-tool for getting height map/artificial erosion, and afterward to put the map into blender to get a 3D topography. That sounds tempting, to let the computer generate to a certain extent, but I don`t want to have too randomly generated terrain. I still want to get to choose where mountains/rivers are... I still don`t get if its the right choice, or if there might be other software like this.
I also think I don`t want to do an assemblage/montage of real heightmaps put together wih photoshop (I can work with Adobe cc, the image is from a .psb file with maxed out size). Someone will notice certain regions and make unwanted connections/narratives out from that and I also have some landforms not so prevalent on earth, like really giant craters/remnants of them. So I`d hat at least to take areas from heightmaps of the moon for that ones, or similar if I went that way...

So... I got a good start for a pretty map, but I`m rather clueless right now how to continue without loosing myself in the project. I hope someone might have encountered similar problems and got something up their sleeves. If its a paid tool, would be ok too. This map is a part of my main hobby project.