First: Your gear ratio of 99:1 is OK. Best you chose at your EasyDriver ¼ or 1/8 step mode.
In the meantime I have done some planeless scans with DAVID 3.10.0 (64 bit). And all worked fine.
Camera: Modified Logitech C600 at 800x 600 @ 15 fps.
Motor scanner: 1.8° stepper with attached planetary gear (ratio 64:1). 1/8 micro step mode.
Chose: 'Motorized Laser Setup'. Set the right COM port. DAVID normally automatically finds the same port as which was used to upload the Arduino code. Check if a hook was set under 'Advanced Settings' (at top to find under the cogwheel symbol). Then 'Communication', 'COM', 'Enabled'.
Do the calibration of the camera (by bright ambient light, switched off laser). Then....
Go to '3D Laser Scanning'.
Adjust a fine laser line.
Set a hook at 'Record New Motion' (= reference scan). Chose a appropriate 'Motor Speed'. Set your self-built controller to 'Auto' (motor and laser).
Start the reference scan: No „rainbow“ colors behind the V-formed moving laser line are visible.
Stop this reference scan at the end of the scan range and start with the very same settings the 'object scan' (No hook at 'Record New Motion' and don't erase the just done reference scan!). No 'Stop' is necessary, DAVID stops at the same position where you had stopped before the reference scan. During the test phase simply scan the walls of the corner.
If the test object scan is ok, you can remove the corner and scan something at the same place where the corner was before. For a new object-scan erase the former one (after it was saved
You can move the scanner to any place you like but take care that camera and laser scanner (motor) do not change its position to each other! Both must be mounted at a stable rig (construction). Otherwise the reference scan with corner must be repeated.
Also objects which have another distance to the scanner as before the corner had, will be scanned. Of course best results will be achieved if the object is about at the same distance as the calibration was made before. Here cam and laser were best focused. And, because camera and laser are not „looking“ along parallel lines but are working together under the so called intersection angle, more far away objects cannot be „hit“ by both devices. But this is necessary for DAVID's triangulation method.