Just my two cents but here is my suggestion thus far.
The Rachel Sanctuary level 1 and 2 spawns are pretty much like what I would expect the map to spawn normally. With the increased crowds drawn to TI events it's almost like any spawn changes seem nonexistent. 3x the spawn and make sure there are no delayed spawns. All spawning monsters should be instant if they aren't already.
Now let's deal with Rachel 3. /swt Having the Hodremlin turnin is nice addition but that's about all it is. You get the potential of staying at lvl 1 and keeping all 3 turnins active at once for Isilla, Vanberk, and Hodremlins and can work on them all at once. But that's about all it's good for. I went to level 3 to try it out as opposed to battling with the KS Kommittee that rules all TI events with an iron fist (gwing).
Level 3 has a natural spawn of 60 as per
Doddler's RODE. So with this event that would equal to a measly 120 on a rather large map. There are 248 eligible quest monsters spawned on level 1. This is a HUGE deterrent to even attempt a harder map as the monsters are harder to deal with. Seekers zap your SP with Mental Breaker and also dispel spam. Hodremlins also divest armor >.> (evenso if you are not wearing armor). If the spawn of all monsters on these maps were doubled then that means you have to battle 80 seekers for a potential 120 hodremlins, not worth the hassle if every mob comes with seekers and the mobs are even worse far and few in between.
Now top ALL of that off with the fact that the 200 hodremlin turnin is less than doing either Isilla or Vanberk and you see how useless it is to level on Rachel 3. The spawn of hodremlins isn't near fast enough to compete with the 1st level of the dungeon. Also being on level 3 limits the player to only completing one TI at a time.
TLDR: Rachel 3 has terrible spawns, low exp, harder monsters, no reward. Fix it.