Dried cedar needles for mulch?

I have cedars. I have the needle? drop from the cedars. (Mixed a bit with other things, but mostly needles.) When I search for cedar mulch, I get conflicting information. Some people say they won't touch cedar as a mulch or decomposition source, but they seem to be talking about the wood rather then the leaves. Other people seem to be fine with all things cedar.

At this moment, I'm thinking of using cedar needles as a mulch to suppress some weeds (mostly dandelions - which I appreciate in other places but not right there) in order to hopefully establish portulaca as a no-or-really-low maintance area. Will cedar needles kill portulaca?

I also want to plant sunflowers near this area. Will that be a problem?

Thanks for your advice.

Same situation here. I recommend you test the PH of the soil where the needles are found compared to another patch. If there's no significant difference in PH then they probably don't acidify the soil that much and would be fine to use.