Relational's hedge funds are in at least a partial liquidation (possibly full, I don't know). This was announced back in October, but I don't see many updates since then. Why they waited so long to start selling shares, I have no idea. These funds are not buying ANY new shares of ANY stock, so they certainly won't be adding to MHR. So one should not just assume they have given up on MHR as there is almost some degree of forced selling going on. Logically, you should want to be a buyer when there is a forced seller, but there's no way to pick the bottom.
They were trying to get their clients to switch into new funds, so they probably didn't know how much they would end up selling. But clearly they waited way too long. No idea if they have to sell the entire position or if they've managed to retain a good portion of their client base and can hold onto a majority of shares. Could get real ugly.
You might want to run some scenario analysis on potential returns of GDPAN vs levered GDP-C. You are definitely making a mistake on the downside risk and it's also very likely you're making a mistake on the upside potential. GDPAN is trading at a higher current yield and less than half the liquidation value of GDP-C. If prices normalize to the upside, GDPAN wins in many scenarios. And if there is a swap offer for common at some point, it is almost always based on par value, not market price, so GDPAN would crush the C and D in returns for that.