Thank you for your interest in BSS extension.
The M2 Advanced Reviews extension works well with every product type, including grouped products. The review of grouped products will display in the frontend as this screenshot https://prnt.sc/rzjr0j
The M2 Review Reminder extension also works with multiple product types, including grouped products as well. The main function of this extension is to remind customers to share product comments by automatically sending them review reminder emails so for grouped products, the customer will receive the email to remind them writing their opinion.
I hope our information is useful to you.
If you have any other queries please feel free to contact us.