Of course I always teach our class to strictly follow the manufacturer’s instructions for your ladder.
Be careful with ladders, a LOT of people are injured on them every year. It is surprising how dangerous the ‘silent’ tools are. Think of ladders and screw drivers, etc. Saws make a lot of noise, therefore they automatically demand a certain level of respect. However, the lowly utility knife (or ladder) can really injure you too. Be careful on the job! If you get injured you can’t make a living.