In Reaper menu Options > Show REAPER resource path..
un-zip to Scripts folder
In Reaper menu Actions > Show Action List > New Action > Load Reascript
open ReaTrak regions to sfz samples.lua

The SFZ will work with lots of different audio formats. If you use wma it needs to be stereo.
Sforzando can't time stretch so it will be the same tempo.

In the BBPlugin create up what ever chord sections you want to use and however long you want them.
Use the C7 button to drag a midi chord track with markers into Reaper (right click C7 for options).
Select the midi item then run
Item: Import item media cues as project markers
SWS: Convert markers to regions (make sure you have
(To manually create regions just select time selection and Shift+R)
remove the first Count-In region

You can have A and B sections as well as endings also.

Drag the wav instrument from the Plugin into a Reaper track and select the item (you can use the stereo mix if you want to sample the song sections).

ReaTrak regions to sfz samples.lua
this will give a print out of the sample sections in SFZ format.
Copy this text and paste it in an new text document in the same folder as the wav, you can get the folder path by right click track item > Source properties.
save the text document, close it and rename it to my instrument.sfz
example: 405 Guitar, Acoustic, Strumming Ev 120 (C).sfz
drag the sfz into Sfozando each region will count from key 0 on the left up.
The sections are set to loop so however long the midi note is on for.