I'm reading the Reaper user guide, and came across something that looks interesting: What if one wants to use a scope plugin (or plugin chain) as a track insert without using XTC (same way as one could use an external hardware unit)?
Here's the quote from the manual explaining it:
It's simple as setting ReaInsert 's send and return to a pair of ASIO I/O, and then route them inside SFP in anyway we like toUp and Running: A REAPER User Guide v 2.5 - Geoffrey Francis wrote: 3.31 Recording with External FX
One special feature of REAPER is the way it can be used to record a track using an external hardware FX device in much the same way as you might use an external device as an insert when recording on an analog desk. It does so by making use of a special plug-in called ReaInsert.
Here’s how it’s done. If you want to try it out step by step, create a new REAPER project file, insert a track, then get your FX device ready.
Example
1. Connect an otherwise unused audio output to the input for your FX device.
2. Connect the output of your FX device to an otherwise unused audio input.
3. Create a new REAPER project files and add a single audio track. Give this track a suitable name. Let’s record a vocal with the FX on it.
4. Connect your microphone to an otherwise unused audio input. Switch on the FX Device.
5. Arm the track for recording. Select the input device (to which the microphone is attached), select Monitor Input and specify that you want to Record Output.
6. Now display the FX Window for this track, and add the FX VST:ReaInsert to this window.
7. Specify the actual Hardware Sends and Returns that you set up at steps 2. and 4.
8. Make sure the FX Device mix is set to 100% Dry, then click on Auto Detect. This enables REAPER to calculate the required degree of delay compensation.
9. With the track’s output directed to your headphones, monitor the required Volume and FX Levels, including the FX Wet/Dry mix.
10 . When you are ready, Record.
11. When finished, don’t forget to disarm the track and set the ReaInsert plug-in status to Bypass.
I presume other DAWs have imilar features...