RTCRtpSender corner cases clarification

Hello all,

I would like to get clarification on two corner case that should be
possible according to current draft:

1.-Send two different media codecs on same RTCRtpSender. In pseudocode

sender.send({
    encodings: [
      {codec: VP8,pt: 100,ssrc:1},
      {codec,H264,pt: 99:ssrc:1}
    ]
})

2.-Send same ssrc on two RTCRtpSenders on same transport given that payload
types do not collide

sender1.transport===sender2.transport

sender1.send({
    encodings: [
      {codec: VP8,pt: 100,ssrc:1},
    ]
})

sender2.send({
    encodings: [
      {codec,H264,pt: 99:ssrc:1}
    ]
})

My understanding is that this shall be supported by all ORTC browsers, am I
right?

Best regards
Sergio