Duration for which late block should be set in OMJI

Hi ,

During production order confirmation , system throws message "Order locked by RFC_USER".

Read that .....through Late block this issue can be resolved .

currently default setting set in system is 999 seconds . As per my understanding if it is set for 999 seconds the material will be locked for long time . Hence can we change from 999 to 10 seconds & what is the impact .