I want to register, but currently in office and they block docs.google.com
Can someone please register my name? Thanks.

Unlike other tournaments which are joined by teams whose players are selected through recruitment process, this is a paksa-rela type of team grouping.
Nobody wants to be a benchwarmer in this kind of arrangement by picking a subsitute in a team. Moreover, this unker's tourney to have fun right?
To resolve this issue in the future, why not allow all the late registers to be allowed second chance to be in the tournament and take over this MIA players as they probably are more serious in joining the competition. The MIA will be kicked out and will not be participating the tourney from there onwards and replaced by the new player.
Admins should already have a list of late registers right? so first come first serve during the start of the match in the event MIA happens.
Win-win for everybody.

being a stand-in players, IMO no need to take down MMR already. the basis to pick the subs should follow the sequence that the players registered and available during the match day. say player number #43 is the highest number available during the day (number #41 and #42 not online in lobby or no longer interested to join), then he gets to play.
the way I look at it is in any case, number #41 or #42 or #43 would already being selected to join the tourney anyways if they registered earlier. but on the other hand, the grouping of each team would be different from onset (if we were to argue on this manner, we will be talking about alternate parallel universe lol).

my wrong choice of word, it shouldn't be 'stand-in' it should be 'replacement player'.
if default lose is given then not fair for the rest of the team coz they are already online and anxious to play but have to penalize because of the MIA.
as I mentioned earlier, if MIA then the player should be removed from the tourney from there onwards and replaced by the next inline waiting list players.