JMM...
I realize your concern and the need to advocate for yourself. There are high risks that dictate chemo: perforation, obstruction, LVI, PNI, Grade 3/4, less than 12 lymph nodes. The only thing that I can suggest is getting a second pathology on your tumor. Was your pathology done at a Designated Cancer Center https://www.cancer.gov/research/nci-role/cancer-centers? These centers are usually at major cancer centers. When you meet with for the second opinion, you might what to ask. You can always request one. The reason being is that Grade, LVI, and PNI is subjective. Having a second set of eyes would be beneficial. I know people, Stage II, that had a second pathology done on their tumor and the results changed, especially with grade and LVI. In addition, I also agree that you should be tested for MSI-H. By doing these two things, you would have a piece of mind. I did not have a second pathology, butt I wish I did. Not that it would change my mind with treatment, butt it would give me more information needed for recurrence.
Beckster