Drain WM (w/ air gap) to kitchen sink or tub?

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I have two ideas, seeking feedback:
IDEA 1: drain WM into sink and monitor with 90 gallons of reserve capacity standing by
IDEA 2: drain WM into 84 gallon tub... both ideas would use a mesh over the drain to prevent debris going down the drain.

My questions:
1. Will I overflow my neighbors? (especially person below me)
2. How can I find technical data (already sent email to LG) about gallons per minute of drainage and min/max gallons used based on weight etc.

I found this thread here: https://terrylove.com/forums/index....e-drainhose-into-kitchen-sink-plumbing.11575/

They "make washing machine plumbing tie in to the kitchen sink plumbing? For example, ... drain into the disposal like the dishwasher?"

Answer: "no" due to:

1. 2" drain GPM vs 1.5 " GPM vs WM drain GPM
2. Trapped and vented
3. lint coming from the washer could block up smaller diameter pipes.

I bought this: WM3998HBA https://www.lg.com/us/washer-dryer-combos/lg-wm3998hba-washer-dryer-combo. I'm a single guy, and probably would just wash a small load once a week.

IDEA 1: This is the route I want the drain water to take:

WM> straight up 84 inches (96 inches is max)> 180 degree curve down > extension plastic tubing that is hard connected to drain exhaust (inner diameter of the plastic tubing is 2.75 inches, which fully encloses the drainage spout)> gentle slope with one 90 degree bend (it'll be curved) towards the kitchen sink>air gap> mesh filter> kitchen sink

How I plan to mitigate the concerns
1. I will stand by (within 20 feet) with TWO 45 gallon buckets. When I hear the WM start draining, I'll walk over to monitor the situation. If the sink starts to over flow, I'll shift the plastic tube to the 45 gallon reserve capacity (I have another electric pump to pump it out). Additionally I would cut off both the cold and hot water.
2. Not sure about this. The manual clearly states to "Never create an airtight seal between the hose and the drain with tape or other means. If no air gap is present [it won't function right]" so I'm not sure what a trap and vent really mean.. Would anyone be willing to educate me?
3. the mesh filter would hopefully prevent debris from getting down into the drain (I also realize this may end up making a clog in the sink, hence idea 2). I would have to empty this routinely, I know.

It is a 4.5 cubic feet front loader. So, if we assume the worse case scenario (filled to the top with water), it will pump the entire machine full of water, which is 33.66 gallons, then dump that directly into the sink, which likely can only hold maybe 5 gallons. My sinks drain rate is 6.4 GPM ** test below**

in-out = over flow =34 GPM - 6.4 GPM = 27.6 GPM of over flow..both sides of my sink hold 4.8 gallons for a total of 9.6 gallons ( I'll position the drain tube to go half and half on each side of the sink). So, 9.8G/27.6GPM = 0.35 minutes, or 21 seconds

Lets assume I react within 21 seconds. HOWEVER, and here is my question... CAN A COMPLETELY FULL SINK OF WATER (9.8 gallons) IN ANY WAY FLOOD MY DOWNSTAIRS NEIGHBOR? I noticed during my tests, the other half of my sink filled up with water, did my down stairs neighbor's sink also fill up with water? I know it wont over flow his sink, but if he just so happens to be standing at the sink while I'm draining, would his sink fill up partially

The reason why I ask is: its an old building, the property manager lives below me, so trying not to start any drama. (not seeking feedback with how I should talk with my property manager, but thanks).

IDEA 2 (drain into 84 gallon tub)
If the WM ever overflows the kitchen sink: my back up plan is to move the WM near the bathroom and drain into the tub (with an air gap into the tub). I measured the tub, it was (at its shortest on all axes) 53 inches x 23 inches x 16 inches... which is 19,504 cubic inches or 84.4 gallons (minimum). Again I would have a mesh drain to prevent any large clumps of debris getting down and clogging the entire system.

Seeking any feedback from yall.. Am I insane to think the sink could even work at all? Is the tub idea equally worthless? I'm still within my return window so I can return it if necessary. But, ideally at a minimum the tub idea would work out. I know it would be a pain to clear the clogs... but, that really isn't an issue for me.

** test, it took my sink 3.17 minutes to fill up 5 gallons. 5gallons/3.17 min = 1.58 GPM is what my tap can provide. I placed a drain stop, placed .1 gallons, then poured in the majority of the 5 gallons.I then started the stopwatch, removed the drain stop, and poured in the remaining water for a total of 5.1 gallons. It took my sink 0.8 minutes to drain 5.1 gallons or 5.1 gallons/ 0.8 minutes = 6.38GPM
Hey, wait a minute.

This is awkward, but...

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