The 52 cent warrants can coexist as the 75 cent warrants get exercised due to differences in expiry.  For instance, if the share price increased to $1 shortly, then the 75 cent warrant holders could only profit by buying shares at 75 and selling into the market. The 52 cent warrants still have some time to expiry and so they do not have to be exercised, these holders can choose to short if so inclined.

All this said, Poet has no corporate need to have the 75 cent warrants exercised, other than the neccessary condition that the share price is meaningfully above 75 cents. I am not concerned that these will likely not be exercised. I am pleased by the measured cadence of positive news releases.