PC to Mac Problems: A Mac port or remake of a PC program can be a hit-or-miss
I've managed to replace some of the programs I used to work with when I was still on Windows with Mac or cross-platform alternatives (i.e. Adobe Premiere Pro which is cross-platform for Windows and Mac unlike Sony Vegas Pro which is Windows-only) and while UTAU also has one which is UTAU-synth, Both programs have their own advantages and disadvantages because UTAU-synth isn't actually a port of PC UTAU but rather a different UTAU program designed for Mac computers, taking advantage of the Mac OS X features.
One thing I like about UTAU-synth is that you can listen to the render while it is actually still rendering and the interface is more similar to VOCALOID in the sense that you don't need to add rests manually and some parameters are found below the notes like in VOCALOID. The downside, you can't use other resamplers and if you do the oto and aliasing on UTAU-synth, you can't just copy it on the PC UTAU.
Basically, I find much easier to oto and add aliasing on UTAU-synth since you can see both the waveform and spectogram at the same time. So, that's what I did, Now, because the encoding of the oto in UTAU-synth which uses UTF-8 is different from PC UTAU which uses Shift-JIS (and that UTAU-synth is using 'oto_ini.txt' as opposed to 'oto.ini'). The aliases became mojibake and I had to manually copy and paste each one via Notepad on Windows instead (as shown above). Well, actually it took me a while to realize that and went scrambling to find solutions (to go as far as to oto again on PC UTAU instead but unfortunately it crashed before I finished and lost motivation to do it all over again - then I remembered having a backup copy of the original oto and decided to manually copy and paste instead)
That's what made me took too long to finish my first UTAUloid - blame me, I'm just starting XD