This is a big job! Currently the new GL2ES2Pipeline supports these image formats, and the switch case can be easily put into the JoglPipeline https://github.com/philjord/java3d-core/blob/jogl2es2pipeline/src/main/java/org/jogamp/java3d/Jogl2es2Pipeline.java#L4480 However the real issue is that the file loading code for these is a very large amount of code - 9 classes in java3d-core package and 30+ in external files, some of which is third party code and it's license status is unknown See: https://github.com/philjord/3DTools/tree/andy/3DTools/src/com/numericalactivity/dktxtools https://github.com/philjord/3DTools/tree/andy/3DTools/src/tools/compressedtexture https://github.com/philjord/3DTools/tree/andy/3DTools/src/javax/media/j3d So some thought will need to go into how to move forward on this.
If this enhancement is done this bug must also be done Bug 1332 - Texture Mip Map count checking incorrect