returnoftheyeti something like this-just general, directional thoughts-might give you some ideas. doesn't specifically incorporate "the loop" but could be opportunities to do so. sentinel peak right near the finish/where you're staying would be a nice way to cap it off.
https://www.strava.com/routes/3171427269143250276
it's not exactly close to where you're staying but consider sabino canyon must-do (along with saguaro np-east and mount lemmon which you've done). you can do any combo as a longer ride since they're all semi-nearby to each other
if you're doing a 40-50 miler starting at either sabino canyon, mt. lemmon or snp-east. also liked the redington pass ride last year as a little side trip in that area. sabino canyon has cycling restrictions like no bikes after 9am and no bikes at any time on weds and sun
or something like that. check online for the latest. because sabino canyon has restrictions, makes it an obvious starting point to knock it out before 9am. allot yourself 1.25 hours for the climb, descent and picture stops if you do hit it.
https://www.strava.com/activities/6615264260
https://www.strava.com/activities/8483383837