Double-checking on the use of Rx and Tx pins

I'm short of pins, due largely to the fact that the DF Robotics LCD uses so many. (NTS: must upgrade to a more modern LCD....)

I'm likely to need to use the Tx and Rx pins, which I've never used before. I know that using them will preclude the use of Serial, which is ok for the project at hand.

But, I just wanted to check the connection practicalities: as far as I can remember reading here, I should disconnect any sensors or activators from those pins during upload, and reconnect when the sketch is uploaded. Is that right?

Otoh I think I read it's bad practice to un/plug pins while the board is live, which is back ass-wards from the above.

Clarity please anyone?

JimboZA:
I'm short of pins, due largely to the fact that the DF Robotics LCD uses so many. (NTS: must upgrade to a more modern LCD....)
Maybe a I2C backpack for your LCD?

But, I just wanted to check the connection practicalities: as far as I can remember reading here, I should disconnect any sensors or activators from those pins during upload, and reconnect when the sketch is uploaded. Is that right?
Yes

Otoh I think I read it's bad practice to un/plug pins while the board is live, which is back ass-wards from the above.
Not if you turn if off before swapping pins.

Looks like the backpack is for a "raw" LCD though?- the DFR0009 unit I have is a shield, with some push buttons.

Ah right... turn it off.... So turn off, unplug stuff on tx and rx, turn on, upload sketch, turn off, plug tx rx stuff back in, turn on. Bit of a mission but better safe than sorry.

JimboZA:
Looks like the backpack is for a "raw" LCD though?- the DFR0009 unit I have is a shield, with some push buttons.
Ah I see now it's a shield so a lot more complex to use I2C backpack.