[mschnell]

The way switching patches with Reaper/Liveconfigs is done like that:

You set up several tracks for different basic layouts of the audio chains you want to be able to use (Midi and/or audio input, multiple channels audio output).

Now via Live-Configs you can on the fly unmute one of them and mute all others (while there of course can be other "non-managed" tracks that just stay as they are.

You can use each these tracks for multiple patches by having LiveConfigs push appropriate "configurations" to the VSTs. You have stored these configurations with appropriate names before, using normal Reaper configuration means.

So no load-time when switching patches.

As muted tracks can be configured to stop the VSTs they hold, theses don't use up any CPU performance.

A special case are sample libraries such as Kontakt instruments. Here it's better not to do a "configuration" switching for any patch (this will make Kontakt (pre-) load the samples when changing the patch). Here it's better to use the internal patch- ("instrument-") selection, Kontakt offers, via "PC"-messages. For this, I did a tiny Reaper plugin (script) that just sends out a PC message when LiveCongigs changes it's configuration.

I suppose using LiveConfigs and swapping project tabs is kind of mutually exclusive. Swapping Project tabs might be a good means - but supposedly not the only one - to manage "background tracks", but it will kill the possibility to decently live-playing VSTi instruments by Masterkeyboard or using VSTs on live audio streams.

For the backing tracks I could imagine either using something like a sampler (which seemingly would need to feature multi-channel output), or user Reaper tracks with the appropriate "song" placed at a certain time position, with having Live-Configs place the play cursor there and start the playback.

LiveConfigs can do any Reaper "action" as well when entering as when leaving a "config" (line).

You can use up to 8 LiveConfig tables in parallel. (I use two, one for each of my masterkeyboard) they can set to react on different Midi Channels. So maybe you could ue one for managing the patches, and another one to manage the background tracks.

I don't know "PIP". Maybe you can report here what you find out about same. I suppose this is something to allow a behavior like Ableton Live, e.g. loop-based live-playing. This in fact might help here. (I already did mention the - not yet existing - "Live SubProject" Reaper feature, PIP sounding like something similar...).

In fact "Live playing" seems to be considered two very different things by different persons: Using VSTs in Reaper "stop/monitor" mode (which I do: "Forte-Mode") and controlling Reaper's play mode in a live performance (e.g. for loop based performance: "Ableton-Mode"). You seem to need both at the same time.

-Michael