GSMPv3 & L2C

Section 3.1.4 in the GSMPv3 draft describes extension TLVs. There is a =
restriction of "at most one extension TLV per message type". Is there a =
particular reason for this restriction ? There might be cases where a =
particular technology needs more than one such (optional) TLV in a =
message. One option could be to have the "extension value" be composed =
of multiple sub-TLVs (with their own well defined format). But, it is =
simpler to allow multiple top level TLVs. Based on the "length" in the =
GSMP message header and the "length" in each TLV, the parsing is not a =
problem. For sanity check number of TLVs in the message can be included =
in the message. The device that does not understand a particular TLV can =
silently ignore the TLV and continue on.
In context of L2C this is needed for a BRAS (controller) to configure =
line characterstics of a DSL line on a DSLAM. There is more than one =
parameter that can be configured (multiple, optional TLVs in the port =
management message seems like an appropriate way to implement this =
functionality). Any thoughts on not having the restriction of a single =
"extension" TLV per message type ?

Thanks
-Sanjay