I am not well versed in the insurance business, so maybe someone can help me out - if I have e.g. travel insurance included in my home insurance, would a second travel insurance (e.g the one with Nordea Plat) cover the excess of the first one (or v/v)? Another scenario if the damage is above the insured sum of one insurance - would the second insurance cover the rest?

I have even seen some insurance marketing that they would cover specifically the excess of another insurance.

PS - this Plat card makes one calculate if one should use Aktia Visa at 1,6avios/€ or the the Nordea card for 0,5c/€ cashback. Using Nordea would value Avios at 0,3c (3€/1000avios) which is outrageous undervaluation of avios, IMO