thanks - love your plugin.
Running W3C validator on my site just gave me two ideas to improve it:
1. duplicate ids
The id for the main fields are duplicated, when you use srp more than once.
why not delete the id atrribute in /classes/class-main.php line 352? This could anyway only result in problems when updating, because I wouldn't use CSS on a changing ID.
2. escaping & to & + amp;
you only need to do this in class-main.php in line 140, 428, 434
I could send you the changes in my class-main.php (v. 1.9.4) if you like