Double Piston Extenders don't(barely) work, and need help making two of them side by side

Question

it takes 3 lever clicks to fully extend it, but takes 1 lever click to retract it. i need a way to make it single click

[Minecraft 1.20.4]

Answer 1

When making a double piston extender, it's important that the second piston (the one getting pushed by the first piston) gets unpowered first (which your repeater timings suggest you already figured out), but it's also important that it doesn't get powered before the first piston has a chance to push it, as extended pistons cannot be pushed. In your design, notice that the redstone dust next to the second piston powers the block it sits on, before the first piston is powered.

to fix this, simply use a block instead of a piece of dust:

you'll notice that the second piston doesn't actually pull the block you would put on it back. to do this, i suggest using a design that is tileable and tried and tested:

I can't remember where i saw this, but it's a canonical design in the redstone community at this point. The only caveat is that it requires a button press instead of a lever input, but if that's really important to you, a redstone lamp+observer turns lever input into button input:

and of course since the design is tileable, making 2 shouldn't be a problem: