Sphagnum moss has gotten a bad rap. People avoid moss because they're scared of root rot and stem rot. This doesn't have to be the case. With these tips, you can prevent rot while at the same time cutting down the time you need to spend on watering your hoyas.
I've learned from growing carnivorous plants that one of the best mixes you can use is 50/50 sphagnum moss with perlite. The sphagnum moss holds a lot of water, while the perlite provides the aeration needed to prevent rot. I use pots or cups with no drainage. This is my way of allowing a water reservoir on the bottom which makes it easier to water the plants less often. This is helpful and saves time, especially if you have a lot of plants to care for. The only thing you need to make sure of is to use high quality New Zealand sphagnum moss such as besgrow. High quality moss takes a longer time to break down and you won't need to repot for years. The low quality Chilean or other mosses break down fast and has probably given sphagnum moss a bad reputation as well.
Sphagnum moss is my favorite medium to root cuttings and gives me a really high percentage of success. On top of that, it's low maintenance and I can ignore cuttings for weeks or longer in a high humidity environment. The beauty in growing in moss is that I can just transfer the cuttings rooted in moss to a larger pot with moss and perlite and not have to deal with removing moss from the roots.
Regarding the size of the perlite, I prefer medium sized perlite, but small and large size works too as well as a combo of sizes.
In summary, I grow all my hoyas in a 50/50 sphagnum/perlite mix. It saves you a lot of time on plant care which prevents you from get overwhelmed, especially if you're growing a lot of plants. I hope you give sphagnum moss/perlite a try and who knows, you may become a fan.