Incorrect thrust
Framer, your assertion that taking off on the short runway with INSUFFICIENT thrust set could feel positively lively compared to taking off on the long runway with correct thrust seems to me, an old retired F/E, to be incorrect. In what way would it seem "lively"? Having had to, by company decree, not been allowed to use reduced thrust on the short runway at YSSY I can tell you a B747 Classic with only 35000 Kgs of fuel (SYD-MEL) and Max Thrust really is lively. So much so that it went up like a lift and the initial climb angle was quite steep so that the first thrust reduction and gear retraction could be completed. I would think that taking off on a short runway with insufficient thrust would be quite "hairy" rather than lively. In fact I don't see any scenario where less thrust than required on any runway would result in better acceleration than with the correct thrust setting.