With the introduction of 16-bit per channel color support in Paint Shop Pro X and Paint Shop Pro Photo XI, some of the features support 16-bit, while others do not.

The following commands and tools support full 16-bit per channel images:

Adjust -> Add Noise
Adjust -> Backlighting
Adjust -> Blur
Adjust -> Blur More
Adjust -> Brightness/Contrast
Adjust -> Channel Mixer
Adjust -> Clarify
Adjust -> Color Balance
Adjust -> Colorize
Adjust -> Curves
Adjust -> Digital Camera Noise Removal
Adjust -> Fill Flash
Adjust -> Gamma Correction
Adjust -> Gaussian Blur
Adjust -> Highlight/Midtone/Shadow
Adjust -> High Pass Sharpen
Adjust -> Histogram Equalize
Adjust -> Histogram Stretch
Adjust -> Hue Map
Adjust -> Hue/Saturation/Lightness
Adjust -> Levels
Adjust -> Negative Image
Adjust -> One Step Photo Fix
Adjust -> One Step Noise Removal
Adjust -> Red/Green/Blue
Adjust -> RGB
Adjust -> Sharpen
Adjust -> Sharpen More
Adjust -> Smart Photo Fix
Adjust -> Soften
Adjust -> Soften More
Adjust -> Threshold
Adjust -> Unsharp Mask
Adjustment Layer -> Brightness/Contrast
Adjustment Layer -> Channel Mixer
Adjustment Layer -> Color Balance
Adjustment Layer -> Curves
Adjustment Layer -> Hue/Saturation/Lightness
Adjustment Layer -> Invert
Adjustment Layer -> Levels
Adjustment Layer -> Posterize
Adjustment Layer -> Threshold
Blend Mode -> Normal
Clipboard -> Clear
Clipboard -> Copy
Clipboard -> Cut
Clipboard -> Paste
Effects -> Black & White Film
Effects -> High Pass
Effects -> Infrared Film
Effects -> Posterize
Image -> Canvas Size
Image -> Count Colors
Image -> Crop
Image -> Decrease Color Depth
Image -> Flip
Image -> Free Rotate
Image -> Greyscale
Image -> Increase Color Depth
Image -> Mirror
Image -> Resize
Image -> Rotate [Counter] Clockwise
Image -> Split to RGB
Image -> User Defined Filter
Layer -> Promote Background Layer
Palettes -> Histogram Palette
Tool -> Blemish Remover
Tool -> Eyedropper
Tool -> Flood Fill
Tool -> Freehand Selection
Tool -> Magic Wand
Tool -> Move
Tool -> Pan
Tool -> Pick
Tool -> Perspective Correction
Tool -> Raster Deformation
Tool -> Red Eye
Tool -> Selection
Tool -> Straighten
Tool -> Toothbrush
Tool -> Zoom