Time registration without allocation

Dear who ever knows about this..

We would like to capture full working hours of our service employees using time registration. Today we are using time registration on the service orders and by that moving cost from the cost center to the service order. Here we use an activity with activity category 1. The time not spend on service orders we would like to capture as well. E.g. Training, conference, travel, meetings etc. With this kind of registration an allocation is not necessary. I considered using activity category 4, and create an activity for every type of activity. Is this the recommended approach?

With this approach I can only make KB51N work for registration. I would have preferred CAT2 as this is already in use. Is it possible to use CAT2 together with activity category 4?

Best regards,

Kim