Every time you export using the AME you get the video you had on the timeline at the moment you put it into the AME.
If you change the timeline video, then export, it will result in two different looking export files.
There is no need to use different sequences if you don't want to. I would probably use multiple sequences so I could more easily go back and make wsome tweaks, but it is not necessary if you are just trying to get multiple looks to show somebody.
I create a sequence and put my AVI file in there and then I just apply the preset.
Then on the same sequence, I clear the preset and apply a new one, and again without rendering, go to export and then to the encoding queue.
Does "apply the preset" mean selecting an encoding preset
before sending the Sequence to the Queue?
If I understand what you are trying to do...
It sounds like you want to do multiple, different format
exports from the same Premiere Sequence.
I would Queue the Sequence to Media Encoder once from Premiere,
then duplicate the entry in the Queue (Ctrl+D) and assign the
different encode types to the duplicates in Media Encoder,
(instead of Queueing the Sequence multiple times).
...will the export files each have the different preset applied even though it was not rendered?
A Sequence will be encoded using the assigned settings.
You can set multiple encodes in the Queue, each with different settings.
I'm not sure what you mean by "even though it was not rendered...".
Unless you have specified 'Use Preview Files' in your encoding,
it will make no difference if your Sequence is 'Timeline Preview'
rendered or not.