I know about inverter compressors, but they cannot defy the laws of thermo dynamics no matter how fast of slow they run. It’s impossible. If it’s too hot outside, the heat will not escape the condenser and will go right back inside rendering it useless and not cooling.
You will only see benefit with the inverter because it can slow down when it’s not hot. If the compressor reaches 45degrees, and it’s 40 degrees outside with the condenser in direct sun, you can’t extracting much heat meaning it’ll take forever to cool.
Refrigerant temps will make a difference, but they still have their limits too. All depends on what’s being used. I assume OP was sold R410, low chance they were given the newer r32 or r454b replacements.