Mobs above Level 35 however have a chance to re agro on you. If they do, they will go directly to you as if you were still an enemy. If you have stayed down long enough for the mob to return to its spawn point, then there is a 90% chance it wont agro on you again. However, if it is still roaming there is an 80% chance that it will aggro on you again. Don't be too worried though, you do have the chance to re-feign and each subsequent feign reduces the chances of re-aggro by roughly 20%. (This info pulled from
P99 Wiki)
Those above 35 sure do feel like they will pretty much remember you every time post FD (they will "re-aggro" when you stand back up). If you remain FD for the entire time it takes the mob to return to the spawn point or pathing point, the mob will memwipe.
Now, here is where the changes come in play. When mobs above 35 are still returning to their spawn point or pathing point, you can attempt to re-FD (FD, wait for cooldown, stand, FD, wait for cd...) multiple times to memwipe. The number of times you re-FD will increase the chance of a memwipe.
"On first [FD] attempt, mob has about 2/3 chance of remembering you. On second [FD] attempt, about 50/50 chance. Each subsequent [FD] attempt will give you a greater chance at the mob forgetting you." -Haynar
Q:Will a mob "remember" you if he has returned all the way to his bind point?
A: If you have stayed down long enough for the mob to return to its spawn point, then there is a 90% chance it wont agro on you again*''
Q: Will they have a chance to "forget" about me while they are still on the way back to their bind spot?
A: All mobs sub 35 will forget every time.*'' Mobs above 35 will now have a chance to "forget" you after subsequent FDs where each subsequent FD benefits the monk a higher chance of a successful "forgetting" event.*''
Q:What were the chances of a mob forgetting you prior to this patch?
A: Pre-35 Mobs: 100%. *'' Post-35 mobs: 80% (-~20% each subsequent FD)*''
The money shot: Post-patch, the initial stand is ~66% chance of reaggro rather than 80%. Successive FDs now have (1st) ~66%, (2nd) ~50% (3rd) <50% (4th) <3rd attempt chance of re-aggro rather than pre-patch: (1st) ~80% (2nd) ~60% (3rd) ~40% (4th) ~20% chance of re-aggro. It seems to buff the initial chances of FD memwipe but the 4th attempt onward really seems to be about the same.
Another way of looking at it is now we have a (1st FD) ~33% chance memwipe (2nd FD) ~50% chance memwipe (3rd) >50% chance memwipe (4th FD) >3rd attempt chance memwipe rather than before: (1st FD) 20% chance memwipe (2nd FD) ~40% chance memwipe (3rd FD) ~60% chance memwipe (4th FD) ~80% chance memwipe (5th FD) ~100% chance memwipe.
(It is unclear what the post-patch % is after the 2nd FD as Haynar did not provide this information. This I am uncertain whether or not post-patch FD gets you to guaranteed FD memwipe sooner than pre-patch FD memwipe. The gradient appears to be 100% - 66% - 50% - X%. Thus, it's initially ~33 then ~16 difference, so the assumption is that it would continually decrease? Or perhaps it could follow a pattern of 1/1 - 2/3 - 1/2 - 1/3 - 1/4 - 0. This would result in the same # of FDs required to reach 0 as pre-patch. It would confirm a "buff" to the initial FD chances and a buff to monk's patience. Note: this part is pure speculation.)
Sneaking while FD has not changed, so the same rules of sneak/FD apply.
*Given you are outside of aggro radius.
''Given you do not fail the FD.