On the crowdsupply product page they explicitly say that the sample rate is 30.72MSPS, If you want to run it outside of specification without adding some major cooling, expect the lifetime of the product to drop exponentially. The relationship between MTBF and temperature is an exponential curve ( The 10 degree rule: Every 10°C increase in temperature reduces the life of electronics by half [or the 18 Fahrenheit rule]). Also from a RF perspective the higher the temperature of a device (and the larger the bandwidth) the higher the noise floor will be due to Johnson–Nyquist noise. In summary - More bandwidth equals more noise and higher temperature equals more noise.
Like I said already, because a LimeSDR-mini has 4 layers of copper less than the LimeSDR-USB/LimeSDR-PCI there will be less grounding/shielding/attenuation between signal lines so random glitches due to cross talk at a higher clock rate are entirely possible.
I don’t think Lime Microsystems are going to explicitly say that you can run a mini at a higher sample rate than 30.72 MSPS, that would legally open them up to extra costs.
In my mind the LimeSDR-mini’s were made as well as they could be made, but with the price point locked in stone. So you could squeeze slightly more performance out of them by spending more money on enhancing them, but there is an upper limit.