If you have the cash to try this one out, it seems to have more sensors. It would involve moving your hair aside and gelling sensors down in several spots.
Can't speak to the specifics, because I haven't tried either. But it looks to collect more detailed, accurate information than the Opti hardware.
https://www.emotiv.com/epoc-flex/
You could do a search here for open studies involving EEG results. Professional equipment tends to be more accurate.
You can also search for more invasive brain imaging/monitoring technique terms: MRI, PET scan, DTI.
https://www.nih.gov/...-clinical-trial
https://clinicaltrials.gov/
As for your spreadsheet, you may just need to export it in a more detailed mode or somehow export all the data. Because it's not possible to visualize with just a single value for each date. And with a lot of those being zero, it makes the data seem even lower quality.
What was the strange pattern? How does it suggest you have epilepsy? Where are you seeing this?