Continuing with my thoughts about your expected outcome and that the 255 Bar issue is always related to BIAB algorithm, not only is your issue with the 255 bar limit of BIAB intriguing, but so is your work flow where that limitation interrupted your projects.
I edited and condensed your comments about the bar limit and your project work flow from your comments in the other thread here on the Forum that focused primarily on the bar limit.
I agree totally with Bob (Jazzmammal)regarding RealBand can become an integral part of your workflow regardless of you also using other DAW's as well.
Although a long standing issue, I think too much focus is being placed on the 255 bar limit. Not as a criticism but as a statement after reviewing your work flow, your current workflow does not differentiate well between the accompaniment audio rendering process by BIAB and the resultant audio considered just rendered audio file. This results in unnecessary and undue time spent when and how you're working with the audio after it's been generated by BIAB and that rendered audio is imported into a DAW be it RealBand, Studio One, Pro Tools, Reaper, Traction, Ableton or Audacity. The DAW is irrelevant other than 1) Realband will be the most productive first stage after BIAB generation even if it's moved to another DAW after that. 2)The importance of any DAW is only dependent to how well you understand it and how competent you can manipulate it.
This is the edited and comments as I've completed them:
... how I use BiaB
This is how my writing process plays into the formation of my idea to increase the 255 bar limit.
I create my songs with MuseScore, an open source music notation program and import an .XML file into BIAB rather than input chords manually. This .XML file contains the complete melody, lyrics, and chords to my song.
The very first song I tried to use with BiaB is a 9-minute long ballad I wrote in January 2013. It consists of an intro, three 12-line verses, a 5-line chorus that is repeated three times, a short musical interlude after each chorus, and a 2-line tag at the end. All of these sections combined total 327 bars.
I started listening to a newly-created arrangement in BiaB. All of the bars past the 255 mark were blacked out. I researched to find out why. Then I tried to figure how to create repeats for the verses, chorus, and interlude to get around this limitation but eventually gave up because of the complications I ran into.
In February, I again used BiaB for a 7+ minute acoustic/rock/symphonic ballad that will be the title track for an album I'm working on with a local producer. Being aware of this limitation and the challenges involved in setting up the repeat function (which I'm still not sure would prevent the 255 bar limit from being exceeded), I created a .XML file with only one verse and one chorus before the bridge. I created a .WAV file of the arrangement and imported it into Traction (a program I am familiar with.) and constructed a full-length version of the song then exported it to a .WAV file.
If I just wanted to create a single demo of this song for myself or to share with others, I would be done at this point. This wasn't the case because I intended to share this song with my producer as my next song for him to arrange and produce for me. Plus, this would be my first use of BiaB to create a fully-arranged demo of one of my songs before I shared it with him. I always provide him a video of the lead sheet for him to play the song on his guitar as the melody is being played in the video.
Every song I've given him to produce, he finds things in the song to be tweaked, changed, or rewritten. The "pre-production preparation process" for this particular song lasted 5-6 weeks during which I went back and forth to his studio about ten times with new demo versions of the song that contained necessary and/or desired modifications, some of which I came up with. Each of these versions required the same process I described plus the additional step of importing the .WAV file of the full-length version of BiaB's arrangement of a new .XML file into another program (ActivePresenter) I used to create the video of the new lead sheet of the melody.
This isn't the full story of what it took to create the final full-length demo version of this song for my producer. One week in particular I spent at least 30 hours repeating the above process because I wanted to provide my producer with several different options for him to consider (one with two different tempos, another with and without a key change for the final chorus, and another with and without a capo on the second fret). I also had to start over twice with the entire process for all of these options because I discovered when I was listening to the final demos that I needed another measure in one or two places in order to make sure the down beat of the drum track didn't switch during a subsequent line. If I didn't have to construct a full-length version of BiaB's arrangement for each of these options in Traction because of the "255 bar limit", I doubt I would have spent more than ten to fifteen hours creating these demos that week. Primarily because of what I went through with this particular song motivated and compelled me to post my idea to fix this limitation.
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There are numerous BIAB and RealBand recording techniques, some that have been mentioned but not explained or discussed and some not mentioned that may benefit how you can more efficiently and in much less time complete a demo and make edits, changes and corrections to the your demos than what happens presently with your projects. Let us know if you'd like to discuss these other options.