Congratulations on the restore.
Sounds like you have a truly scale flying model
As to the question as to if there is a truly correct decision?
There are many truly correct ones available to you.
1 - Leave it as is and fly "Scale".
2 - Remove the existing engine (and ballast) and replace it with the higher powered option
3 - Go somewhere in between 1 & 2
All are corect decisions, only you can decide what you prefer.
If you like doing Aerobatics, go for more power. If you want to learn about scale flying - leave it as is.
If it was mine, I would be looking to see if there was anything I could relocate forward (or change) to reduce the tail heaviness first. That would have the benefit of reducing the wing loading. If there is nothing that could be done practically, I would go for the DLE20 that you have as you can then also do things such as run a smaller fuel tank and an IBEC and "perhaps" end up with a (very slightly) lower overal weight.