I think the reason why Waterloo has such a fascination for many compared to the Peninsular, is that it directly pitted Wellington against Napoleon. Throw in other personalities like Ney, Picton, Blücher etc. It was also the battle that finally spelled the end of Napoleon.
I like the 100 days campaign and will continue to buy and request sets for it, regardless if sets already exist. I am not someone who says "its already done-so dont need it", as I am someone who believes "more the merrier", not to mention theres a lot of sets out there that are complete rubbish.
However I too would love to see more Peninsular War sets. As you say, we need British light & heavy cavalry for a start, as what got released (after an age of waiting), was poor indeed.
Sorry to hear you have caught covid. Fingers crossed it doesn't affect you too badly.