If you haven't planted in the soil yet, sure you could mix 1 scoop perlite to 3 scoops HF. That would help. I've never used HF, never handled it. I can't say how much perlite to add. I tend to over-do it with perlite because I like my soil to dry in 2-3 days (faster wet/dry cycles). If it were me, I'd probably mix it 50/50. But, that's just based on what I've heard about it being slow-drying, prone to root rot. I could be entirely wrong about it. 25-30% be reasonable.
Ocean Forest seems too nutritious for me. People say it's not as long as you don't feed on top of it (until around week 6). But, even then, some of the plants I've seen (growing just in OF, without additional nutrients) looked a little on the overfed side.
I like light, airy soils. My soil is essentially soiless (Pro-Mix HP) and 25% rich soil added (plus 25% perlite. HP has 35% perlite. The rich soil I add, Kellogg Patio Plus, has about 5% perlite). It dries in 2-3 days when a plant has grown into the container.
I'm growing in Kellogg Palm & Cactus right now. It has almost zero nutrients in it. It's drying in 18 hours. That's a little to fast for my tastes.
Anyway, I've always steered clear of soils with nutrients already in them. I'm not the right person to guide you on OF or HF. I like to feed each watering (and water frequently due to rapid wet/dry cycles). I like to vary the NPK ratio and dial in what the plant is eating. Almost like soilless, but I like to have light "soiled" nature to it. (I'm planning to do that with the cactus mix an see how it works). Even though it's a light soil, I feed lightly. Only about 200-260ppm.
BTW: Happy Frog is reported to be 0.30-0.30-0.05. Ocean Forest is reported to be 0.30-0.45-0.5.
The bags don't come with that NPK label. But the Washington Sate Dept. of Ag. has a database of product analysis. That's what it shows for those soils.
The soil I add to my soilless is 0.30-0.10-0.10. I only use 25% to the nutrientless Pro-Mix HP and extra perlite. That gives you an idea how much my style differs from growing in straight OF or HF.
But, you should be ok. As long as you give it time to dry between waterings; don't start feeding until week 4-5; start feeding very lightly (50-100ppm). Watch your plant as you increase it. I would also watch the runoff ppms from the very beginning. That might produce some useful info if you continue growing in HF. Sometimes you can see trends, like amended nutrients being exhausted as PPMs go down. Or, salt buildup if they go up as you feed. With my soil, the ppms are like a canary in the cage. I know exactly what runoff PPM results in nutrient lockout. I know the soil ph base upon how high the runoff ppm is. My feeding "schedule" is dialed in based upon that.