piece in the pic is just found on the floor

This checks out. Even with all of my storage and shelving, I have found the floor to be a nice place to go parts shopping. JST bits are at the top of the list to find, usually. (What was that? You never bought any? You’ll find some, don’t worry.)

Do you need a bit of wire to patch a trace? Take your shoes off and walk around a bit and you will immediately find a lead you clipped off a through-hole component in about 15 seconds, even though you vacuumed 6 times since you lost it.

Bad bot.

Jesus is supposed to be dead. If you are meeting up with dead people, you have issues.

Like someone else said, pull all the LEDs. There is no point to them if you don’t need them. Just because a pin is set low doesn’t mean it’s completely off, so cut any unused paths to ground to be sure. LEDs still have to reach a specific forward voltage to turn on, but they could still be passing a fractional amount of current.

I believe the internal pull-up resistors are 10k, so if they are enabled, you can disable them and save a few more fractional pennies. (Maybe 3uA per pin if the pullups were enabled to start. Lulz.)

From a software perspective, you just need to keep the MCU in sleep mode as much as possible. Rely on the internal timers to wake up and sleep the MCU and make sure that the main loop is looping as slowly as possible.

That MCU should have an internal oscillator, so test it to see if it saves you any power. Turning it on and disabling the external oscillator should drop the clock speed down to 8mhz and might save you a bit more juice.

I tried finding the video, but I cannot.

It’s the same concept as potting PCBs with black epoxy. Of course, it helps to be aware of heat sensitive components but China never cares about that.

Google for Epoxyseal 9000, if you want something proper.

Adding on to this line of thinking, maybe a thin plastic tube and epoxy to encase it with the solder joints. (Bonus points for using thermal epoxy, since it is a resistor after all.)

I have seen Bigclive on YouTube encase resistors and a diode rectifier in standard epoxy for use in lighting, so heat probably won’t be an issue now that I think of it.