High engine power is damaging, therefore you should only use the OEI ratings when you really need them. You may need the 30 second rating to get to Vtoss (which shouldn’t normally take anywhere near 30 seconds, unless you are eg winching) and you may need the 2 minute rating to get to Vy and maybe climb a bit. After that you can back off to continuous. And after that, you only need to use the 2 min or 30 second ratings if you slow down below Vy/Vtoss. Which you shouldn’t do except for landing.
So the question should really be “how little can I use the OEI ratings”, not “how much can I use the OEI ratings”. And also you should bear in mind that these ratings are created as part of the certification process and to comply with the certification process, the manufacturer probably only needs to demonstrate that they can be used once in an engine failure on takeoff, once for a baulked landing go-around, and once for the final landing. After that, the engine can be toast according to the certification requirements and you are into uncharted territory.