I’m not really familiar with that game or system, but I do know that there are games on other consoles of that time period that would use 240p for gameplay, but switch to 480i for title screens and menus. If that’s the case with Crusader of Centy, there’s not much you can do about is; it’s an unfortunate side effect of HDMI. Basically, resolution changes interrupt the HDMI connections, and then the HDMI devices all have to reconnect to each other before video will display again. This generally results in significant delays between menu screens and gameplay.
If the lack of seamless resolution changes really bugs you, you’ll either need to play on a CRT, or try out something like an EDID minder (not sure if this adds lag) or a presentation switcher (definitely adds lag).