While I agree with you in most of the cases, an evasion set is in my opinion pretty important still. Against 1-3 mobs (in Dyna), there's no need to use anything other than the pure DD gear, but an evasion set is extremely useful in case of a bad pull that ends up linking 4-5+ mobs. It's the difference between ending with a bunch of currency and kissing the floor mid-run, with the subsequent weakness etc.
That's about the most reasonable situation I can think of, but I still don't think I really agree. Going into full evasion mode just means you take longer to kill mobs, and spend a longer time with a bunch of mobs beating on you where a couple lucky crits can take you out. When I get a link I prefer to try to kill excess mobs ASAP, and Cure VI spam plus emergency Role Reversal seems to generally do the trick for me. Even if you did consider an evasion macro, I would probably just use a couple of strong evasion pieces that still retain DD benefit (say, Ocelot Trousers, or Ocelomeh Headpiece) as opposed to a full-on max evasion set.
If it's a truly huge link, the delay in killing stuff in eva gear (if you even survive) is often going to add up to a few minutes wasted anyway, lessening the blow of just dying quickly/safely, RRing, and dealing with 5min weakness. And the worst case scenario is that you waste a couple minutes TRYING to fight through a 4-5 mob link, then they kill you anyway. Then you have the full 5min weakness AND wasted time from trying unsuccessfully to kill the mobs. Almost better in my mind to accept you screwed up, die quickly/safely, RR up and get back to work. If possible, use the downtime productively - change camps depending of time of day, hunt down other TEs if you aren't already at 5/5, etc. True, a death may cause a little hit to your farming totals, but we're talking about dealing with weakness for 1/24th of a 2hour run - not really a catastrophic loss.
Also, don't link 4-5+ mobs, etc. :) Generally my only PUP Dyna deaths come from linking mage beastmen and eating spells. Nothing you can do PUP/THF but hope you survive the nuke, -ga wrecks /NIN, and /DNC you at least have a better chance since you can Violent Flourish to stun spells, but you're often riding that timer pretty hard. Edited, Apr 23rd 2012 6:01pm by Anza