I already discussed using “distance field font rendering” for this in another thread, but used this shader because the implementation seemed overkill for what I wanted to achieve. (see 2D outline pixel shader on a pixel font)
I actually tested the performance difference between the shader and not drawing text at all. It was almost no difference. I currently have 400 - 500 fps on a 3440 x 1440 resolution (while also drawing 33k tiles) so framerate is not a problem (yet).
But thanks for the advice 
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