Can you use Latrite like Flourish tabs? Just freeze a little Latrite into a small cube stick under and/or near the plant/s needing root fertilizing.
Laterite and flourish tabs are quite different actually. One is essentially clay, the other is a solid fert mix of NPK and some traces and other things.
Some people will make "clay balls" similar to Flourish tabs. However, laterite by itself is supposed to be a layer of substrate that slowly over time will provide root systems with need iron.
So the answer is no, not exactly.