If you’re on a bike and need 5 cm of spacers, it isn’t the right frame for you .
Using that as a basis to purchase another frame isn’t the right thing to do.
If you respond with “it fits me fine” then you don’t need anyone’s help in choosing an 18-D.
Maybe take this opportunity to do a myvelofit or get a bike fit.
I agree with this. I'm normally a "you do you" no-unsolicited-advice guy, but since the advice has been solicited, well...
I'd go further and say that if your current position is a proper fit on the Tan Tan then you like a short reach and a tall stack. I'd be looking at frames that put your hands, feet and butt i the same relative position to the bottom bracket with fewer spacers and a slightly longer stem (if possible).
Unless you're truly confident that your position is optimized, the suggestion to get a bike-fit is good advice.
You may be able to find LCR018 that fits you, and you may not.