generic approach to Bandhelper, ideas?

[TauTau]

I'm currently looking at perhaps using some advanced tool for our on-stage setup. I think it's easiest to explain what we are currently using/doing, and I then hope to get some hints at how bandhelper could assist us.
First of all, we don't use regular notation, for guitars we developed our own style of documentation (think of it like tabs). After all, we make black metal, we're too dumb for real notes
We use a lot of backtracks (even the drums come from the laptop), from within reaper (each song is opened in its own reaper tab). Since we're quite old, we have a track with colour coding to show where in the song we are. I as guitar player have a PDF which resembles the same colour codes with that mentioned guitar-tabs. I view that PDF on my phone, each song fits on a screen (if needed, I can give screens/graphics that explain more detailled)
Our singer has a paper notebook that he switches pages manually between songs.
I switch between songs in reaper using a foot-pedal, that allows song-forward, song-backward (i.e. switching the reaper tabs), and play, that pedal uses PC-keyboard simulation which I set in reaper actions (so it sends for example "A", "S", "D").

so the big question is, how could I streamline this setup using Bandhelper? The easiest parts probably is lyrics, I've already seen how that works.
But how should the sync between reaper and bandhelper happen? Should I start Bandhelper via pedal, and it then starts reaper via Midi?
Also maybe interesting, we're currently implementing our own lighting, but since this will probably be controlled via Midi from reaper, it's quite integrated already

here's hoping on innovative ideas (don't refrain on complex technical solutions, I got a 30 years IT background and can understand a lot I think )

[arlo]

It sounds like your custom notation is already in PDF files, so you could attach those to your songs in BandHelper.

I would leave the backing tracks in Reaper, but instead of stepping forward and backward through songs there, send MIDI from BandHelper to Reaper whenever you select a song to load the corresponding song in Reaper. Then you could use the foot switch to step through songs in BandHelper, or click a song title on the screen in BandHelper if you want to go out of order.

Then you can build set lists in BandHelper and since BandHelper will display the correct documents and load the correct Reaper songs for you, you won't have to rearrange your paper sheets or rearrange your Reaper tabs for each set list. So basically you will have instant access to your PDFs and your Reaper projects, whether you are following a set list or skipping around to different songs. And those set lists will sync to all the band's devices automatically. So making a set list becomes a one step process instead of requiring several additional steps to get everything up to date.