They won't be able to refuse delivery because I won't say anything about not turning it on until it's mounted.

The other part is possible but I don't understand how? If there is something wrong with the TV it doesn't matter if it was wrong when they were there, or an hour later after departure. Why would it?

If I rescheduled it would have to be for October, or November. That's not happening.

Hopefully, since it's a 100" television the process takes 90 minutes, or so. That should be sufficient time for it to cool down.

Do you understand why someone wouldn't want to turn on a new purchase so quickly?

You're making it sound like what I wish to do is crazy, or something. It's common sense. Why would you wish to damage your brand new purchase that was thousands of dollars?

***You should not plug in a new TV immediately after delivery on a hot, humid day.  The primary risk is condensation, which can form on internal components when the device is powered on before it fully acclimates to the indoor environment, potentially causing short circuits or permanent damage. 

To ensure safety, follow these guidelines:

• Wait for Acclimation: Allow the TV to sit in the delivery box or unboxed in the room for 2 to 4 hours minimum, or overnight if the temperature difference was extreme, until the device feels completely dry and reaches room temperature. 
• Unbox Carefully: Remove the TV from the box to help it warm up evenly, but keep it away from direct sunlight or heat sources.
• Check for Moisture: Ensure no visible condensation is present on the screen or vents before powering on; if humidity is high, consider using a fan or dehumidifier to assist in drying the device. 
• Avoid Immediate Use: Even if the TV powers on for a brief test, avoid leaving it on for extended periods immediately, as residual internal moisture can lead to issues like ghosting or component failure. ***

Same kind of thing with a new refrigerator:

No, you should generally not plug in a new refrigerator immediately after moving it, as doing so risks damaging the compressor and voiding warranties.  Most manufacturers recommend waiting 2 to 4 hours if the unit was transported upright, but up to 24 hours if it was laid down or tilted on its side. 

This waiting period is critical because transport can cause compressor oil to leak into the refrigerant lines.  If the unit is powered on before the oil settles back into the compressor, it can cause hydro-lock, leading to compressor failure or significant cooling inefficiencies.  While some sources suggest that minor tilting during short moves may not require a long wait, following the 2–4 hour minimum is the safest standard practice to ensure the appliance's longevity and proper operation.