Change 'true' to 'false' on contract line?


below line is in my contract:
_isExcludedFromFee[owner()] = true;

can I just replace 'true' by 'false' so that I won't be excluded from taxes as the owner?


yes, why not? Or just remove the line or instead just try it out yourself.

Post deployment, you cannot do it.
Need to have function to change the value.

Yes, but I did not yet deploy.
So I can change it to 'false' or even just remove the entire line, correct?

Correct, by setting it to false the owner will also pay taxes