Can push in connectors be used for parallel circuits?
&quot;old yellow cap twists&quot; - if you hate the things then use something else.
However you should hate the old ones. Old wire-nuts aren't very good, or to be more precise, newer ones are better designed.  I throw away all old wire nuts especially Scotchloks.
The other reason to hate wire-nuts is if you have not learned proper technique.   If they don't firmly hold together by themselves, you're not tightening them enough, or wrong-size nut for that many wires.  I stock yellow and red, that covers just about everything.
Never, ever tape wire nuts. Or to be more precise, never need to tape wire nuts. A proper splice must easily pass a &quot;pull test&quot; (hold nut, yank each wire one at a time).
&quot;Backstab&quot; connections on receptacles and switches are known to be unreliable.  Some here will vouch for the stabby splice, but keep in mind those &quot;came free with the lights&quot; which isn't the highest recommendation in the world.