V Bit engraving patterns - very rough sides

Do a multi pass program. If your total depth is 1mm, try a first pass at 0.8 and a last pass of 0.2mm. That should help.

Also try different feed speeds. 360mm/min is pretty slow for 1mm depth in my opinion.

For my 3mm 90 deg V-carve bit from stepcraft (SKU 10105 from https://www.stepcraft-systems.com/en/accessories/insertion-tools/v-router ) I have used following parameters:

Diameter: 3.0 mm
Included Angle: 90
Pass Depth 1.0 mm
Final Pass Stepover: 4.2%
Clearance Pass: 25%
Spindle Speed: 18000 rpm
Feed Rate: 1500.0 mm/min
Plunge Rate: 500.0 mm/min

I also have the 60 deg V-bit, but I use the 90 deg most....

Here is some examples of the Wolfram cube stand I made. The triangles are made with 90 deg and 60 deg V-bits. The extra lines visible on one of the sides is because the stepcraft lost some steps in Y-direction between roughing pass with 3mm end mill, and final passes with 60 and 90 deg V-bits.

The other example is a dragon I have been V-carving with 90 deg bit several times (first seal the wood with clear lacquer, then paint the top black, and then V-carve the image).