Taking kinetic readings for the Briggs–Rauscher oscillating reaction

I am current doing the IB diploma program where we are required to do an extended essay which is a form of a research paper on a specific subject. I chose chemistry.

I am analysing the kinetics of the Briggs–Rauscher reaction, adapting my experiment from the paper by Schmitz and Furrow [1].

The paper appears to use a spectrophotometer to measure iodine concentrations which I have tired, however the readings failed since the reaction needs to be continuously stirred. Another alternative they have used is to use an ion selective electrode to determine iodide ions in the solution however I don't have access to this. I do have an AgCl reference electrode and was considering trying method from this YouTube video, however I lack a potentiostat and the ion-selective electrode. I was wondering if anyone could tell me any tricks on how to build this electrode if possible as I couldn't find anything online.

Alternatively, is there any other recommended way to determine the kinetics of this reaction. I would like to not have to use a stopwatch to clock the oscillations since that does not provide me with much detail.

References

1. Schmitz, G.; Furrow, S. Kinetics of the Iodate Reduction by Hydrogen Peroxide and Relation with the Briggs–Rauscher and Bray–Liebhafsky Oscillating Reactions. Phys. Chem. Chem. Phys. 2012, 14 (16), 5711–5717. https://doi.org/10.1039/C2CP23805E.