I live in the US. I know soooo many little Sebastians and several Jaspers! I don’t see them as british names at all. I say [name_m]Sebastian[/name_m] as seh-BAS-tyan or maybe seh-BAS-chyan and I’m from the east coast US. I honestly know more little kids named [name_m]Sebastian[/name_m], [name_m]Oliver[/name_m], [name_m]Leo[/name_m], [name_m]Theodore[/name_m], etc. than I do the Kaydens and Landons and all those names you listed
Wow. I disagree that those names sound at all “crass” in an American accent and that the American accent is only good for the names you listed. Not to mention, there are a myriad of American accents and they don’t all sound the same. However, use whatever names you like and pronounce them however you like. It’s ultimately up to you. The ones you will likely have the hardest time getting people to say “correctly” in the US are the ones ending in R, as I’m sure you know. It is just not very natural for Americans to say [name_m]Al[/name_m]-iss-tuh (not exactly accurate, but I can’t figure out how to spell the soft British R appropriately). If you want Sub-bazz-ti-an (which isn’t even how I’ve heard British people pronounce the name, for what it’s worth), then pronounce it that way and correct people when they say it differently.