KJ, love your sense of humor
Let's look at that idea a bit ...
Say you tap the required receptacle off the circuit feeding the equipment.
If tied in after the disconnect, there will be no power when you have shut the unit off for servicing. Kind of pointless.
If tied in before the disconnecting means, there is the issue of breaker sizing. You really can't put a 15 amp receptacle on a 40 amp breaker.
And, let's not forget that they usually don't have a neutral present ... which means that they're going to be tempted to do something 'clever' to 'make it work,'
Now, let's look at that cord.
-Cords not to be used in place of permanent wiring;
-"Temporary" limited to 90 days;
- Overcurrent protection suitable for wire size. Many such cords are #16;
-"Branch circuit wiring" must be at least #14; and,
-Such installs typically have poor / improper strain relief where they connect to the box.
Now... to be a 'wise guy' ... if the cord were 26 ft. long, woulf you consider the 'outlet' to be outside the 25 ft. requirement?