Always …. Let the host soil do the initial feeding without adding anything for a few weeks. It is a soil that is nute dense and plenty for a plant to feed on.
Basically a water only soil.
As far as TRIO - there are better options ( not so concentrated ). That line of nutrients can lead to heavy salt buildup if you are not careful.
Not to sound like a broken record on FFOF soil , but you literally can just add more fresh soil on top of container when needed to basically recharge what was exhausted by plant.
As far as burn - it can be from the soil alone or from you adding even more fertilizer to that soil- just water it as needed ( not soak or flush ) and let plant work through it. Allow plant to use excess up at its own pace - make sure your grow environment side of things is good ( temps / RH ) and let plant drive the car. Good temps and Rh facilitate growth too ( transpiration/ etc. )
GL