Hello. I was able to find a way to get C00 demos to run in Demo/Trial mode on a modded PS3. How would i know this? Because i want to experience limitations of what a PS3 game demo has from the past, i looked through google searches and there is a reddit post about disabling the C00 demo unlocker on Evilnat CFW, and the only comment there was from a reddit user who says No. I was thinking of a method and based on from my past history of PS3 hacking, i was able to come up with one that actually works.
For those that don't know, newer CFWs and newer versions of PS3HEN have a C00 demo unlocker that is enabled by default with absolutely no way to turn it off. Every time you just try to just launch a C00 demo game on Evilnat CFW without unlock PKG and RAP installed it will default to the full game. No matter what you do even if you use OFW mode feature. Besides, the game (as long as the full game is compatible) should run in demo mode on RPCS3 when no unlock PKG and RAP is installed.
So to address this, this is only possible with hybrid firmware and PS3HEN. If you're using a CFW-compatible PS3 (any PS3 that has a minimum firmware requirement lower than 3.55/that was manfactured before 2011), if you're already on Evilnat CFW, you can proceed to install littlebalup's Dualboot/Hybrid firmware, followed by PS3HEN. Before doing this you must uninstall any plugins that only work on CFW, for example, CCAPI (which i don't need because it slowed down startup times for me until i uninstall it), or it might soft brick your console. If you're using a PEX version of Evilnat CFW, you must convert your console back to CEX first. Tutorials for using Dualboot firmware or Dualboot/Hybrid firmware can be found here and also here.
And before you ask, what is littlebalup's Dualboot/Hybrid firmware? Littlebalup's dualboot firmware is the same as official firmware, while the Dualboot/Hybrid firmware is basically the same as a hybrid firmware which includes the exploitable web browser from 4.82 official firmware. The difference between is that "isoldr" and "spu_pkg_rvk_verifier" in the firmware is patched to allow reinstallation of CFW, no bgtoolset or hardware flasher is needed. Dualboot firmwares are only meant for any console that is already running on CFW.
To get C00 demo game to run in demo mode, after C00 game is installed, make sure that no unlock pkg or rap is installed. After this, soft reset your console and then launch the game as normal. The game is now running in Demo/Trial mode. This is the only method to get C00 demos to run on a modded PS3. This method for a CFW-compatible PS3 combines Littlebalup's Dualboot/Hybrid firmware as well as the same method i used on a CECH-3001A (2011 model) with PS3HEN to get Feeding Frenzy 2 (2009 release before 2012) or Retro City Rampage (pre-DX version) to run in demo mode. There is no need to do any hacking of the game to force it to run in that mode.
This method should work with any C00 game and should work on any modded PS3, CFW for any PS3 that is CFW-compatible (models that have a minimum firmware requirement lower than 3.55/that are manfactured before 2011), and PS3HEN for newer unhackable models including any PS3 Super Slim model, and should be useful if you want to play demo version of the game downloaded from PSN and stay in that version until you got around to purchasing the full version, legitimately from PSN. This method is not for real demos (non-C00) that need an actual DLC PKG and Rap to unlock the full version (for example, Doki-Doki Universe, WipEout HD, Minecraft). This method may also not work on any PS3 that is modded with qCFW. This is not a trick, you can try this for yourself . . . it's real.
Examples