Hi, that was me. I didn't claim I could fix MRC start-up, only that I was working on a similar problem for another old alt-coin wallet (Lebowskis/LBW). I have a branch of Lebowskis with many v0.8.x Bitcoin fixes applied. It was a lot of work, and I do have everything compiling and linking. There is new start-up code applied, and I am currently throwing an assert in there causing the application to quit immediately. My hope was that once I was able to get these patches to work there I would also try to apply them to MRC. This is unlikely to happen for a few weeks at best, namely because I'll be doing some summer vacation soon.
On a related note, for both LBW and MRC-- wallets with many transactions also experience additional slowness in the form of the wallet beginning to take 100% of single CPU. This is due to wallet verifying new blocks/transactions vs thousands of private keys. New wallets handle this more efficiently, but still ultimately also need to carry out the comparisons. I had this LBW wallet with about ~14,000 transactions which besides being pegged at 100% CPU usage, first slowed down then stopped functioning (beyond expected timeouts). I had not ever done this before, but I needed to "Sweep" all of my transactions from the wallet. I did it all the coding myself, and that wallet took 7 or 8 full-block-sized transactions, but I was able to get it done and now the wallet is purring along at 10-20% CPU usage, which is reasonable for an active wallet.
So, for anyone having troubles with wallet with lots of transactions-- you need to sweep those transaction into one giant block, which will reduce the overhead of the wallet and marginally increase start-up time as well. Here is what I used: https://github.com/CaptEmulation/bitcoin-rpc-sweep. I have not tested on MRC, but it should work with any bitcoin RPC. I'll test it with MRC later today.