I don't know about building another version of Classic from the ground up.
http://youtu.be/N3J2PZzuA0w
Here is a video of some functions I coded for Zelda Classic.
Its just more scrolling functionality, demonstrating warp return points and the like. (Also looping world map for Epoch, [you might want to skip from 1:50-2:20] which is fully functional and cannot land on solid combos even. I am aware that the enemy death graphic is a small boy.)
My PC is a little outdated and not very powerful, so please don't hassle me about the glitches/bugs.
The overall speed and everything of the engine is just fine like this.
Since my game doesn't use one single built in combo flag or anything like that (aside from Solidity), a build of ZC with all those things factored out of it would make a great game engine.
This code I wrote could actually replicate Chrono Trigger to the T, but it plays more like Zelda and looks like Chrono Trigger due to the fact that I haven't wrote a battle engine (yet) and probably won't.
Let me know if you're interested in having this file for yourself. It does what is described that 3.0 will be able to do with 2.5. The difference being that I overwrote combo flags to get it done instead of it being hard-coded into ZC.
I will only send the file via PM per request in an effort to keep it off the database pages so people don't see it and start using it thinking there will be updates for them like its 3.0 alpha build or something.