Sliced front buffer rendering on MALI GPUS

I developed a custom front buffer rendering method for VR that supports vertex displacement distortion correction:

https://github.com/Consti10/FPV_VR_2018

therefore i need to render half-screen slices dirctely into the fron tbuffer, similar as descrbed here:

https://www.imgtec.com/blog/reducing-latency-in-vr-by-using-single-buffered-strip-rendering/

While rendering half-screen slices into the front buffer is no problem on QCOM GPUs, because they have a usable extension (

QCOM_tiled_rendering) I am unable to archieve the same one MALI GPUs. Is there a way to render half-screen slices on MALI GPUs
without performance cuts because of half-screen clears ? E.g. like Google does in Daydream ?