I’m well aware of this, I’ve been here since early access and have put more than 6000 hours into this game playing pve/pve-c/pvp on both official and private server 
Still what you are suggesting will prevent those that have old characters from moving to a different server unless they are willing to create a new so-called “Profile Character” and level it, learn all the recipes once more, and for what?
Doing the same as they do now just way more limited, how do you think the majority of players would react?
The Isle of Siptah is an expansion, and we probably got it because people always wished for a bigger Exiled lands map, but the engine used in the game can’t handle bigger maps, so a different map was the only option to expand the land.
In my eyes the perfect expansion map would be a map where you could travel freely to and from, bringing some luggage and take home some souvenirs, you know just like when you go on a vacation in RL, but you are suggesting that we can only do it butt naked, both ways!
So instead of sort of being an expansion with some connection, it just sort of turns into 2 games with different biomes but same game mechanisms, however with the same character, but only bringing your wisdom, knowledge and nothing else.
I don’t think this is what the majority of players wanted, and I don’t think it would go well if Funcom changed it to this.
There was a lot of talk about how a character transfer could be before it was introduced.
A lot of people would have loved it to be connected servers, meaning sort of sister servers EL & Siptah servers connected in pairs with free travel between these, if so I think a lot of people wouldn’t mind not being able to bring anything if they moved their character to a different pair of servers.
I understand that your idea probably would fit better with pvp and maybe pve-c, but for pve it doesn’t offer anything other than less than what they have now, and since pve is the vast majority of players, I think it wouldn’t be a wise move by Funcom to limit the character transfer even more than it currently is 