You got it right, tax implications relate to ISO treatment, but for NSO as far as I am aware there are no direct tax implications unless the NSO are granted to someone in a country where there's a tax-favored scheme that has similar requirements as ISO (e.g. NSO qualifying as EMI in the UK), but that's very uncommon.
The main disadvantage as you state is that options take longer to go back to the pool. To mitigate that, what we see in a few companies is what we call "variable post termination exercise period", i.e. after a certain number of months/years of tenure employees get a longer post termination exercise period.
Hope this helps a bit.