So, what do you think my DC voltage Input Range can be if the IOTA is rated 108 to 132vAC?
I think it's only safe to use it for about 1.4 x 132 = 185 VDC.
(But this converter was used at one time for 240vDC!!) which gives us about 170vAC specs.
My guess is that the input capacitor(s) is(are) rated at 200 VDC. It seems that this sort of capacitor will withstand a short term overload, but the life decreases rapidly when used over the rated voltage. Unfortunately the failure mode for electros that are overvoltaged is a bang, smell, and mess (which could corrode other components). So while you may get away with using it at 288 VDC for a short time, I would strongly advise against it.
You could replace the input capacitor(s) with say 350 VDC version(s), but the switching transistors and other components are likely also not rated for this. Semiconductors usually avalance (and melt) within microseconds of overvoltage, so maybe you'll get away with it, but the first spike on the pack voltage (e.g. back-emf from a contactor dropping out) could take them out.