Does anyone have any insight as to whether Mass Save will start providing incentives for spray foam? 

I know they have not generally covered it in the past, but the 2022-24 plan (https://ma-eeac.org/wp-content/uploads/Exhibit-1-Three-Year-Plan-2022-2024-11-1-21-w-App-1.pdf – page 97) indicates they are developing it:

“Expanded Insulation Solutions.
While the core RCD Initiative measure and service offerings have proven to be attractive and appealing solutions for the vast majority of market-rate residential customers, the PAs recognize that there are some technical opportunities where alternate methods and/or materials may be a better technical solution or preferred customer approach.  An example of this is spray foam insulation. Historically, spray foam was more of a niche product that was cost prohibitive and only offered by a limited pool of contractors. Currently, with wider adoption in the market and a broader trade ally network installing spray foam, the PAs believe the time is right to add this product to the RCD Initiative. There are many types of spray foam; each with its own pros and cons for specific applications, each having manufacturer-specific installation requirements, and costs still at a premium to conventional methods and materials, such as targeted air sealing and cellulose insulation. For these reasons, the PAs intend to introduce spray foam as an eligible measure for specific applications when it is clearly the best technical solution such as for “hot roof” applications when there is mechanical equipment and/or ducts in attics, for crawl space treatments, and for antique homes where framing dimensions and spacing are irregular. Incentives for these new weatherization measures may differ from those that are already offered, in order to motivate customers to select the most economical solution that can appropriately serve the need. The ultimate goal is to have a framework that is easy for customers and contractors to understand, has minimal administrative burden to implement, provides incentives to custom projects that are equitable to the core offerings, provides a pathway to reduce lost opportunities for efficiency solutions, and meets cost-effectiveness requirements.”