If I do the TC lockup switch trick on my '01 Cummins Ram, will it only lockup manually by flipping the switch then? Meaning it will no longer do it automatically?

It will still work normally when switch is off as long as you don't cut the wire from the PCM.

OK, thanks. No plans on cutting any wire...just install the jumper wire in place of the relay and the additional switched ground spliced onto the PCM wire.
Using these instructions...
http://www.tstproducts.com/Torque%20Converter%20Lockup%20Switch.pdf

My truck feels so much stronger when the converter locks it's ridiculous.