It's just the app notes I see using inverter logic, and the examples I have used tend to use Meg ohm value resistors

Hi,

Yeah I've seen them with 10 megohm resistors for feedback.
Maybe it matters but not that much because the input resistor will be lower and that will mean the input impedance seen by the feedback will be lower too and not as much dominated by the capacitance but by the input resistor value.

 

We no not know the very important supply voltage. The absolute max supply is 7V but Nexperia (Philips) recommends a max of 6V for a 74HC04.

A 74HC04 inverter is not recommended to be used as a linear amplifier because it draws a current of typically 48mA when its output is 3V and its supply is 6V. Then each output Mosfet heats with 3V x 48mA= 144mW and there are two output Mosfets heating in each inverter causing a total heating of 288mW.
The max allowed heating in each inverter is 25mW and the max allowed heating in a package of 6 inverters is only 50mW.