I've read it so many times it must be true
When evaluating test strips I take this into account and deduct an arbitrary amount (usually 1 sec), then deduct a bit more for dry down (usually another 1 sec)... while doing the final test enlargement, I might change my mind again...
On timers... I used to use a mechanical (Novex) that repeated times (whatever length) accurately, but was not accurate (ie. 10secs on the dial wasn't 10secs, etc) The problem was compounded when you did you test strip at say 3secs and decided you liked the 4th segment... now is that 3x4=12 (ignoring the above factors) or something else... (which it was). I now use a digital (Durst Labotim) and the difference in ease of use is huge. If I print something I've done previously, I'm pretty confident of the exposure times I've recorded in my notes.
However, if what you're doing now works for you, stick with it.