So, you're trying to reinvent limits? Nice, but you're some centuries late in that.
Yes, the singularity of 1/x can be "removed", even on the complex plane if you add an infinity point to make it a sphere, it becomes a simple reflection
Now Riemann's function is a wee bit more difficult

( ∀𝑥 𝑥 ∈ (0⁺, *0⁻) ) ⇒ [( 0 ± 𝑥 = {0⁻ − 𝑥, 0⁺ + 𝑥} = {−𝑥, 𝑥} ) ∧ ( *0 ± 𝑥 = {*0⁺ + 𝑥, *0⁻ − 𝑥} = {−*𝑥, *𝑥} )]
It is
not an infinity point (coric), for such a point would
not accomodate conventional mathematics hyperreal numbers. Instead, it is an
originone that has been missed sorely.