[Amps] Two quick loading questions

[George KB2Z]

I'm sure I'm not the first to ask. I have searched in the archives and did 
not find a solid answer. I apologize up front and am not trying to waste 
anyones time. The directions from different  manufacturers dont seem to 
answer one way.
As I read the loading instructions for gg hf amps, (2x3-500) they should be 
fully loaded at full power then the loading increased 5 to 10% to lower the 
Ig and help stabilize the output. This seems to be where it gets confusing 
for me.

1) After increasing the loading 5 to 10%, should the plate be re-dipped?
2) If drive is reduced from 100 to 50W, should the plate be re-dipped.

Thanks in advance,  George KB2Z