Patch 7.11 Kindred Question

Kindred's Mounting Dread got the Pantheon Heartseeker buff, where it automatically crits on targets at less than 15%, which has great synergy with her ultimate leaving enemies at less than that. However, THIS critical is only 50% dmg bonus, not 100%.

Question: If Kindred was built with a high critical strike chance, does the chance to naturally critically strike with this ability for 100% exist?

OR is it capped at 50% bonus, making it impossible to confidently build critical strike on Kindred?

And how does this work with Infinity Edge?

The BEST case scenario is natural critical still exists, but a non-critical would code into a 50% increased damage crit. Anyone know for sure?