I have been lucky to hatch a small number of angulate / bowsprit tortoise (Chersina angulata) babies. Here are pictures of some of them.
A few weeks old angulate tortoise hatchling.
This angulate hatchling, incubated on coarse vermiculite, has pipped and made some progress opening the egg shell. He stayed like this inside the egg for two days before he stepped out.
Angulate tortoise babies of various ages, colors, and patterns. Interestingly, these are all from the same parents. Babies get darker and more colorful as they grow.
Comparison of angulate tortoise (left) and golden Greek tortoise (right) hatchlings. The angulate baby already displays the dark, triangular pattern on his marginal scutes. The golden Greek baby has a more yellow colored shell and skin.
My newly hatched angulate babies spend their first few days in a warm incubator nursery. Once their bellies are healed, I move them to a baby tub.
I provide both dry and more humid areas for the little ones. The food and water area is kept cooler and dry while the warm end is kept more humid with deep, diggable substrate and/or with humid plant areas. My babies love to hide in the warm, damp sphagnum moss under the basking bulb.
During the day, the basking bulb heats the damp sphagnum moss. A UV fluorescent tube is also turned on for part of the day if the babies haven't spend any time outdoors that day.
In the evening, I turn off the basking bulb. On a rare occasion during an unusually cold winter night, I may place a low wattage CHE above the damp sphagnum moss. Most nights, I use no night heat at all because the temperature in my tortoise room usually stays above 68-70 °F even in the winter.
Some keepers raise their angulate babies in warm, humid vivariums and have reported good success with that method. It may be worth a try if you have trouble with humidity.
Newly hatched angulate babies will spend their first few days in a warm incubator nursery. This one's a Hovabator.
A simple setup for hatchlings. The tub in the photo is for baby Greeks, but I keep my baby angulates the same way. Both baby Greeks and baby angulates love to dig into the warm, slightly damp New Zealand sphagnum moss. The food side of the tub is cooler and dry, and the substrate side is warm and damp.
You could also raise the top shelf higher and hang the lights from it instead of laying they on the top of the shelf. That makes it easy to adjust the bulb heights for correct basking temperature and UV exposure.
Coconut coir, plain soil, a mix of the two, or something similar, could also be used as the substrate, but they are much messier and harder to keep away from food. You want to avoid any accidental ingestion of substrate with food to prevent impactions.
My angulate babies like to burrow into warm, damp sphagnum moss.