I think what you have right now with the SVS is a slow (and limited) proxy solution enhanced with a 2.5 years end of life PHP version to modify data on the fly. This solution does not scale well in terms of speed and memory. You will need some (new) entry point that uses a lightweight parallel approach (e.g. co-routines) to process more calls with a smaller footprint in less time; which is extendable and ready for the future. Right now the SVS is running into a problem and becoming THE bottleneck for future versions.
