Currently EDGE does not use camelCase RTP codec parameters (it uses packetization-mode rather than packetizationMode and so on). Also, there is no proper "conversion rule". In SDP land we have parameters such as sprop-maxcapturerate, useinbandfec and L that are mapped to spropMaxCaptureRate, useInbandFec and l forcing the implementation to keep a map of them (as here).

But, at the end, not even EDGE implements the ORTC camelCase syntax. Given that having a different naming provides zero benefit here, why not keep untouched the SDP naming?

Also, as @aboba pointed:

Since Edge implements both WebRTC 1.0 and ORTC, developers found it very confusing to convert SDP codec parameters back and forth from camelCase.

(definitely I'm one of those "confused" developers...).