Yep, Id say reducing the heat to 50% was too much - too soon to start with.
You will find that it might ramp a bit quicker initially (depends a bit on your mains voltage) but that isnt of significant concern...... you need to get into FC and RFC with a fair amount of heater power..... 50% wouldnt be enough. At about 70% and less the ramp seems less dependent on the mains voltage..... so if you had reduced to 70% the rate of increase would have been similar to the one provided.
Id say you were hearing mainly FC..... you normally wont get into SC until about 203 on the display (which by the way is actually about 213-215C if you have a bean mass temperature probe....
You need to be a little more aggressive!