I do the test that uses the powder when I am testing because the target that I am shooting for (4 ppm minimum) is nearly impossible to read on the drop based OTO test. If ind that the OTO test is fine to tell me IF there is chlorine in the pool, but not HOW MUCH chlorine there is in the pool.
However, if you have a SWG pool and need to keep FC at 1.5 to 2.0 ppm, I think the OTO would be fine.
I notice that you are in Houston, so Welcome! I suspect that you do not have SWG since it is not in your signature. Therefore, in this area you will be keeping CYA at about 50 ppm most of the summer and therefore your range will be like mine. My pool is at CYA 45 now and so my FC range is 4 min, 8 goal. Your pool is just a bit larger than mine. In my pool, a jug of either 10% liquid shock one gallon on jug of 6% bleach at 96 oz will add just about 4 ppm to the pool. I'm not sure what the new 8% jugs actually add as I've stuck to the Liquid Shock recently. I keep those sorts of things on sticky notes inside the test kit box.