that probe looks to short to me, the tip i thought is meant to be in the middle , my koso shows egt at about 630c and think it is safe to go up to about 700c , melting point if i rember correct is about 730 ? cht stays at around 160-190 c this is also on a rb
Your probe should be nearly in the middle of the pipe.
However the main issue is the way you are reading it. EGT's will vary greatly from different set ups for the reasons of 1) different exhaust types (hot pipes, colder pipes etc), 2)distance from piston skirt to probe, 3) how far probe is inserted into pipe (oooh errr missus!) 4) quality of probe (some react to temp change quicker than others).
An EGT is useless on its own without doing plug chops at various temps to see when it is leaning off or richening up at certain temps or having a dyno session and recording the normal operating temps.
There are guideline temps, but i have seeen EGT's vary dramatically from one bike to another.
For example my mates, like yours will run at about 400 degrees when cruising in the mid range, but on mine, if i was cruising in the mid range and mine was reading 400 degrees my bike would be spluttering and fouling plugs all over the place.
Dont rely on EGT's on their own. They are great when you know your bikes normal operating temp but when setting up do plug chops, choke tests etc.
An EGT can read very low when the heat is being retained in the head and piston and not going out via the pipe...........for example on too advanced timing, so too cold can be as bad as too hot!
Remember, its just an indicator, like a cylinder head temp gauge you need to know the normal operating temp of your set up before relying just on the EGT gauge.