Please do not remove 5%€ it is used in Swedish layout. Both 4$ and 5% are in base, so why would you change one for another?
The Swedish layout also uses the
E€ key, which is the euro sign's standard placement in that and all other layouts that can use
5%€ (SE/FI, NO, DK, IS, FO).
5%€ is a non-standard key that isn't used in all implementations of the Swedish and other layouts, whereas
E€, being standard, is present in all of them.
Now, I would ordinarily not suggest the removal of this key because some users, like yourself, may prefer to have it. However, this is an extraordinary situation since the kits have been finalized and adding extra keys is likely not viable at this point. UK users (which make up a significant portion of the total ISO userbase) are currently disadvantaged compared to all other groups supported by the NorDeUK kit — they are missing keys and sublegends which are required for full support of their layout, whereas all of the other supported layouts have all of their keys and sublegends. In this case, I think it's a reasonable compromise to swap
5%€ (which, again, is a non-standard and partially redundant key) out for
4$€ in order to give UK users full support for their layout.
I hope you understand.