While it is technically possible to run an oval or elliptical chainring with your TRS or LG1 Chainguide the chain retention capability of the guide is diminished. This is is due to the gap which opens at the slider location as the narrow part of the ring passes thru the slider. 

One should also note the max ring capacity of the chainguide will not be the same as when running a round ring. A guide with a 34t max capacity may only be able to accomodate a 30 or 32 tooth ring depending on the profile of the ring.