I give you an example:
Training a 185 cm SG (22 y) in single position training in OD, may give you a skill up every 2.3 weeks of training. If the soft cap kicks in and changes it to 3 weeks, it is likely that you will not notice this before 5 weeks of time. With such an effect however, you may decide that it is still worth to train player. However, if it chages to 4 weeks for the next skill up (still a soft cap), you will start to be quite discouraged. At the same time, you will notice earlier that there is an effect.
There should be somebody out there that could share with us his training diary.