My 9 month old is great at getting onto all fours and backwards crawling (not forwards yet) in his cot. His cot meets Australian safety standards, however he does get his feet caught (even in a SIDS safe sleeping bag) in the cot slats. He likes to sleep on his side and will occasionally roll into his stomach and we will adjust him accordingly. Is there any way of preventing his feet from getting caught? Are Airwarp mesh cot wraps safe for sleep? Would love some suggestions on this, as at times he gets anxious and somewhat distressed, even when half asleep.

Most babies will be rolling over by 4- 5 months. This is very normal as babies grow & become stronger.
Many babies then prefer to sleep on their side or tummy.
This is not something that needs to be stopped. It is important to make his new environment as safe as possible.

Ensure that the mattress is firm & flat & there is nothing soft or loose in his cot.
It is important not to use bumpers (or other soft padding) in the cot, as he is learning to roll.
Many babies will hit the sides of the cot &/or get arms or legs through the slats, particularly when they are learning to roll.

Does he wake when he gets his legs through the slats or does he self settle?
Most babies will just go back to the tummy, their position of comfort, if you try to roll them back.

Always continue to place baby on back to sleep.
Increasing tummy time when awake may also helpful.
If you are still wrapping him this need to be ceased - he needs his arms free. I am assuming the sleeping bag you are using has arms free?

Red Nose has the following information now that your baby is starting to roll.

Give baby extra tummy time to play when awake and supervised as this helps baby to develop stronger neck and upper body muscles which in turn enables them to roll back over.
Make sure that baby is on a firm and well-fitting mattress that is flat (not tilted or elevated).
Make sure that baby’s face and head remains uncovered (do not use lambswool, doonas, pillows, cot bumpers or soft toys)

As babies grow and develop they become very active and learn to roll around the cot.
At this time, continue to put them on the back at the start of sleep time, but let them find their own position of comfort.
By this stage it is not necessary to wake during the night to turn baby over to the back position

Do not use any devices designed to keep baby in a particular sleep position.
https://rednose.org.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over
Parents are generally concerned about the potential for injury from the infant bumping up against the cot sides, or getting an arm or leg stuck between the slats.

Mesh type bumpers are unlikely to reduce impact of child hitting sides of the cot, unless they are soft & padded.
Red Nose does not recommend using soft & padded bumpers in the cot.
https://rednose.com.au/article/at-what-age-can-i-introduce-cot-bumpers-and-pillows

United States Consumer Product Safety Commission data has shown that infants suffer essentially no long term injuries from contact with cot slats.
If you do use this product, ensure you follow the manufacturer’s instructions in relation to installation to reduce the risk of entrapment.