You could do something like this with your #4s:
https://theunraveledmitten.com/2024/01/02/2024-crochet-along-terrific-textures-throw/
Since each block is a different stitch/pattern/texture, it would probably be ok to throw in some random other fibers and weights. Or if the chenille ones just don’t quite look right with the worsted, save them up until you have enough to do a separate chenille blanket.
For the chunky chenille, I have found that just doing straight rows of single, half or double crochet and alternating colors makes a nice blanket. Let me see if I have a picture of the one I did recently.
Found it:
View attachment 4279534
I didn’t have enough of the pink multi color to make a decent sized blanket, but I was lucky enough to find the blue at Goodwill, so by striping them, it was big enough.