One of the biggest things would be that people using macs would actually be able to play it. Tyrano is supposed to have the ability to export projects for mac, but it's been messed up for over a year now and I don't think the devs are gonna bother fixing it :( Basically, the stuff it exports for mac only seems to be playable for a small number of users, most report being unable to get it to start. The devs know it's an issue, they've known for a long time. The last I saw, they just sorta stated that macs are awkward and it's not their problem, but someone else reckoned they promised to look into it in a future update... they've promised a lot of features in future updates that just haven't seen the light of day, sadly >.< It wouldn't surprise me if there weren't any more updates.
Whereas the engine I'm using now is constantly being updated by the dev + new features tend to get added when users request them.
I would also be able to export for Linux, which can't be done with Tyrano.
I know that there aren't that many folk using macs to play stuff like this compared to windows users, but whenever I get someone on mac comment on the GxB version saying they really wanna play it but it won't open, it kinda breaks my heart that I can't do anything to help :(
I guess it would probably be easier to put the other reasons as bullet points so I'm not writing a giant wall of mushed together text here, haha.
- As you said, performance should be better with the new engine, as a lot of Tyrano games appear to be a bit clunky on that front with massive lag on startup (SR takes 9 minutes to open on my old laptop just cos it loads the whole thing at once instead of scene by scene) + bugs like the game crashing sometimes when using the skip text function, layers sometimes randomly reordering themselves for no apparent reason, and other small bugs.
- Audio config in Tyrano is slightly broken (when you change volume levels or mute audio, it reverts back to the way it was when you enter a new scene.) This is something that can probably be fixed if you know how to code (why their own code for default config is broken though I don't know!), but there are no tutorials on how to access the code for config or edit it.
- There's no separate audio channel for voice acting in Tyrano, so if you want to mute or lower VA volume, you also mute general SFX (and vice versa) as they have to go on the same channel. In the new engine, not only is there a separate channel for VA by default, but it's possible to set it up so that the player can also change volume levels of different characters individually in config. With SR being fully voiced, it would just be better to have more voice control options.
- Creating custom UI in Tyrano is a nightmare (all I've done in SR is edit one of their templates to make it slightly more unique, but it still looks kinda ugly to me, especially the choice buttons.)
- Options for character movement/animation + background transitions + special effects are limited in Tyrano unless you have coding knowledge (and I bought Tyrano in the first place because I don't know much about coding since it advertised being able to make games without knowing any code.)
I'm sure there are probably more things, but it's almost 2am here and my brain is a bit frazzled, haha. Those are some of the reasons why switching to the other engine would improve the project overall though :3 Also, cheers for the support :D