Well, @classical retro , knitting on 5 means exactly what you say, though strictly speaking the knitting is on 4 needles because the 5th travels round, as it were.

I have tried knitting one item from the outside of the ball and one from the inside but the yarn has to be untangled fairly often which would be more nightmarish with that number of needles as well.  If the yarn is a 100g ball, you could wind off 50g of yarn using kitchen scales to get the right amount.

Still not saying 

Woo hoo! I did a tension square for some leftover wool and, wonder of wonders, it came out exactly right for the pattern. That NEVER happens! Only problem is that I haven't got enough for the whole job.

Brilliant @toileandtrouble ! I was wondering what to do about slippery bottoms 

Neither do I @Lilian - it's all part of the fun 

I like K2 P2 rib. It always seems cosy and looks neat.

P'raps it's the 2020 swap and has been in isolation for a year