I have noticed that the latest SVN for Pak128.Britain uses the ( and ) keys for changing the level in underground mode. When I tested this, I found it awkward to have to use the shift key, and that they did not always work properly. I suggest that they be reverted to the Pak64 defaults of HOME and END thus:
# sliced underground
toolbar[0][20]=simple_tool[15],9,^U,K
toolbar[0][21]=simple_tool[15],,HOME,I
toolbar[0][22]=simple_tool[15],,END,D
pak64 defaults are ( and ) according to pak64 SVN (I copied the lines straight from there). I can understand why HOME and END might be better, but not necessarily for laptop users, and not necessarily a good idea to use different keys in different paksets by default. The user can always change to suit his/her preference. So if pak64 and pak128 go to HOME/END, I'll change it.
Hmm, that's odd - the original suggested version used HOME and END. PAk64 must have been changed.