works just fine per the documentation...you have to increase the height of the default figure window or it won't display all of them, but will refresh when do enlarge the window.
The timestamp isn't a very conducive variable; what's the encoding to convert to datetime?
findpeaks graphics won't work directly; you would be able to save the peak locations and add the markers, but if want to use some of the more in-depth features like the half-width plots and the like, those will be somewhar more of a challenge.
I've never dived into the detail plotting code to see if it could be munged to plot into an existing axes or not -- hold on works for an existing axes; you can get access to the y-axis properties (limited subset) of the stackdplot object axes, but I do not believe there as an axes handle itself that can be used as a target to add additional information onto the plot...not sure, I didn't try anything here now yet.
If you have ambitions along that route, I think the nexttile route may be the way; you can get an axes handle to each tiled axes from it.
puts them all on the figure (again, you'll have to increase the vertical height) but with the default parameters for findpeaks it finds and draws peak locators at every uptick in each time trace so the plot is just a big blob of down-facing triangles--you'll have to use judicious selection of parameters to only locate peaks of interest.
But, the graphing itself isn't of any real problem it doesn't seem...