All Legrand plug molding is rated at 15 amps yet kitchen circuits are 20 amp with 12 guage wire. How do I make this work. Connections inside plug mold need to be "butt type" as there is no room for wire nuts.
The fact of the sockets being 15A (common) instead of 20A (T-neutral) is nothing to worry about.
15A receptacles are allowed on 20A circuits, per NEC 210.21, provided there are 2 or more sockets. I mean sockets not receptacles: The common-as-dirt 2-socket receptacle is 2 sockets.
Interestingly, a Wiremold outlet strip counts as 1 receptacle even though it has like 20 sockets or something... not relevant to a kitchen, but some places in Code (and for houses in some local Codes) you must provision 180VA per receptacle and/or have an 8- or 12-receptacle limit per circuit. So those plug strips are a fun "cheat" to get a bunch of sockets.
This only becomes an issue if you are trying to plug in an appliance that has a sideways neutral... and when's the last time you've seen one of those?
According to the Legrand spec sheet they have lots of variants available, including 12 AWG or 14 AWG, and including alternating receptacles between two circuits. So if you get the right stuff then there is no problem satisfying both the 20 A rule (by using 12 AWG wire and connecting to 20 A breakers) and the 2 circuit rule. Of course, you may have additional circuits elsewhere in the kitchen and use Legrand for just one, etc. - the possibilities are endless. But stick with 12 AWG and you're good.