Flue pipe temp vs stove top - is this ok?

Hi All,

I'm curious what I should be expecting for a flue pipe temp (external reading) vs a stove top. I feel like my draft is too strong and is sucking the heat out of the insert a bit too quickly.

The secondaries seem a bit more strong/fast than I'd like, although I am burning almost exclusively pine, so that may have an impact. Typically I have temps like below.

450 STT liner 275-300
550 STT liner 350-375
650 STT liner 400-450

Those liner readings are on flex liner about 6 inches above the insert.

I know it is typically recommended that the reading be taken about 18" above stove top but I can't do that with my insert...I can only see about 6 inches worth, the rest is above the blockoff plate.

So are those temps ok?
How much difference is a reading at 6" like I am vs the recommended 18".?
What do those liner temps suggest for an internal exhaust temp?

I should add as I don't think it was clear, those temps are an external reading with IR gun

Good to know about the IR gun readings. Thanks! What's the best way to get pipe temp on a flex liner above an insert?

I could try taking the temp at the flue collar. It is cast iron. If I recall it typically read about the same as the liner but I will recheck on my next fire