[NTG-pdftex] removal of some extensions -- yes or no?

Dear list, I am considering to remove some extensions I added to pdftex recently, as it's hard to make them work reliably, and they also seem little useful. In short they are: ,-------- | \pdfadjustinterwordglue, \knbscode, \stbscode, \shbscode: | adjust the interglue space according to the charater before | the glue | | \pdfprependkern, \knbccode: auto-insertion of a kern before a char | | \pdfappendkern, \knaccode: auto-insertion of a kern after a char `-------- Before I make a decision, I would like to listen to other opinions. So please let me know what you think of this. Thanks, Thanh