I need to know where to make the adjustment and how much? Should it be less in the first segment or less while wrapped and how much?
If you have a good instant read therm, such as a Thermapen.
Check the IT of the ribs in the meatiest part, being careful not to hit the bones.
At 195 IT they will be tender & juicy, but not quite FOTB.
Are you cooking whole spare ribs, St. Louis trimmed spares or loin back/baby back ribs? How much do the racks weigh, on average?
id say the biggest adjustment is just time, ribs have a pretty small window of doneness. id say if you cut your cook time by even 15-20 even 10 min you'll notice a huge difference. when i cook ribs the last hour im picking them up and feeling how they bend. when they have a nice soft bend they are usually done, if they flop they are over cooked .
but even when you take them off they are still cooking, so you may take them off when they are perfectly done. but while they sit in your kitchen they are still cranking along at 190-200 degrees they overcook. it just takes time and experimenting with how long you cook them and when you pull them off