(Mobile format will be a bit off)
1. Double batching is against the standard. Something something quality and I think they used to talk about allergens when we had a non-dairy blender pitcher. I don't remember the exact reason, i think its because the blender cycle is meant to get a certain ranged volume to a certain consistency, and double or triple definitely leads to larger ice chunks. However... 1.5 blend gets it pretty close to standard

2. Its actually dangerous to do this. Some stores its necessary (my first store didn't have a bar with a hot water spigot, register got the cup of hot water for Americanos first so they were technically Long Blacks and we're actually rated better than regular Americanos as the taste is slightly different). Some stores can handle it if the area is wide so you don't risk bumping into someone and spilling ~200-201F water on someone. The bar hot tap is slow af but its there for a reason. I would get a cold brew going in the meantime as they were next to each other or hand off a drink while it was going.

3. Shots "die" after 10 seconds was started long ago to help partners sequence. Its supposed to help sequencing and throughout. Shots don't "die", but they do age and start to cool quite quickly and some customers can tell the difference if its been long enough for them to age, like 20s or more and its a drink like an Americano or plain latte where Espresso is the key player not other junk. You're also supposed to be staffed enough to have two baristas if you're using the machines for that many shots but I mean....

I get its annoying asf, but they've probably had the DM ride them about stupid things, or an SM looking to go upward and trying to get the store into tip top standards.