I completely understand. Unfortunately we can’t really avoid the minimum spec situation, just hope that the development team continue to optimize the software so it’s compatible with less expensive systems.
Some things to do to help if machines are struggling with performance is to lower the graphics setting where possible.
Game Maker: recommend using Full Screen or Window over Borderless Window as it tends to run faster, and the lowest resolution you can comfortably use. It won’t look as nice as max resolution, but it is probably the biggest factor in improving framerate.
When in Playtest mode, press the Esc key and go to Options > Video and set the quality to Low. This will reduce the render distance (far away objects will disappear), and lower shading and effects quality, which will help reduce the strain on hardware. You can also adjust window and resolution settings here. This is the same way to change the settings in the Game Client.
For VoxEdit there aren’t any preferences to change, but you could try making the window smaller so there are fewer pixels to render. In general don’t try making very large assets out of a single model, instead use the rigging tools to connect several smaller parts where it makes sense. Performance is often tied to the total number of voxels being processed. So if you are making a tree, having the trunk as one part, and the leaves at the top as another part, instead of making one giant tree VXM. In this example, there are 65,536 voxels (filled and empty). But in the second example there are only 38,116 voxels (filled and empty).
This example is a little bit simple, I wouldn’t expect either of these trees to perform very differently, but the example scales up. Making a whole building that’s many meters in all directions will be a struggle in VoxEdit. The largest size single model in VoxEdit can be up to 256^3 (that’s almost 16.8 MILLION voxels), and not only can VoxEdit run slow while editing these larger single-chunk models, but uploading can take a really long time. I was once tasked with making massive buildings as LAND owner rewards and it took over 45 minutes just to process and upload any time I made a change. Using blocks in the Game Maker instead, and then using separate assets like doors and windows to assemble in the game will be a lot more efficient (and even flexible for level designers) than trying to make a whole complete building.
I also recommend checking out MagicaVoxel - it’s free and very light-weight compared to VoxEdit, and the files it saves can be opened in VoxEdit for uploading to The Sandbox marketplace just fine. It doesn’t have the animation rigging tools, but it’s a better program for modeling overall. Unless I’m using VoxEdit’s built in templates for characters, I usually start in MagicaVoxel, split into all the parts I need to rig together, import to VoxEdit, set up my skeleton and animate the already finished model.