I don't know how a convention would fix the issue of political parties imbalance.
That is an issue no one wants to touch right now. Everybody is in a purge the immigrants mood because of the offsite recruitment situation.
Dispensing with that for a moment lets look at the reality.
The problem is the status quo population wise is not sustainable from a political standpoint and thus the game is not sustainable because sooner or later constantly losing is going to have a devastating impact on the game. No one is going to play a game that almost completely cannot win.
Equilibrium has to be restored. For most of last year I openly said as many will recall, that any chance for an equilibrium was in a Biden administration driving more conservatives to join the site and hoping in the meantime that we could "hold out" until Biden took office. As you will recall this statement was what prompted the Fairbol challenge to my chairmanship back in June because it wasn't direct action now. That should illustrate the appetite for change now and the impatience with waiting for this process to occur naturally (assuming it does at all and I have heard compelling arguments that it won't because of the preference for echo chambers these days).
The oft repeated line on lokcord by the talking heads there that "the Feds need to move left" or the "Feds need to move center" won't work because unlike in RL, their is a close personal dynamic among most of the Laborites, even those in the center and so at most you gain a couple of votes and Labor still has a dominant edge. Certainly not enough to replace those you would lose on the right in doing so. There are more dissidents on the far left then there are on the center left.