Hi, was wondering at what age or skill level is it recommended/advised to stop using a sleeping bag for babies?

There is no specific time when a child should stop wearing a sleeping bag, apart from the risk of a child using them when no longer in a cot
If a child is wearing a baby sleeping bag whilst sleeping outside of a cot be careful! A child wearing a baby sleeping bag and not confined to a cot is at a higher risk of falling and being injured. The child must be actively supervised and the sleeping bag removed as soon as the child wakes.

https://rednose.org.au/article/making-your-home-safe-before-moving-a-child-from-a-cot-to-a-bed
For more information on Cot to Bed Safety download our brochure here.