Ohh come on man,it only takes around 15 to 20 seconds thats all, but if you want to do that you can either download the PSN version of the game (not all games are PSN i think...) or you can use the (last game PKG) which allows to play the last game you were playing from XMB without entering Multiman & thats it.
In kmeaw and mulitman you could make a pkg that would make a shortcut from the hard drive where your game is and place it into the xmb just like a psn game. Just easier for the kids to find there games. Now I am on rogero 4.40 and the pkg's that I did make don't work. Same games. Plus when in mulitman now it has the feature to make shadow for pkg so just wondering?
I don't think that would work either. Sometimes these have to do with the firmware itself (Not the Custom modified firmware, the firmware in general).
Games like MW3 won't run on 3.55 because the Core_OS isn't support and requires an update. If the developer of a specific CFW would update the Core_OS, it may give support for additional features. I no longer develop much on ps3 firmwares anymore. So I couldn't tell you a straight forward diagnosis of the problem. Its been a few years.