There's an interesting side effect of this system which I think means that it would have lessened impact on the policies implemented by the elected officials.

As in his example, pretend the Kitten party appeals to 10% of the electorate distributed evenly across districts. So in roughly 10% of districts, the Kitten party would earn a seat, but would only represent 10% of their constituency.

In this case, the incentives of the elected Kitten party representative shift. Instead of keeping to their Kitten party ideals, they would seek to maximize their following within their district by shifting to a median political position. This would ensure them the maximum likelihood of re-election in the following campaign.

So theoretically the actual policies coming out of each district would still represent the median view of the electorate in that district, and the Kitten party would remain disenfranchised.