In this manuscript the authors have synthesized original terpolymers and thermosets via ring-opening metathesis polymerization (ROMP) which contain either polyethylene glycol (PEG) macromonomers or dicyclopentadiene (DCPD), pentafluorophenyl (PFP) substituted monomers, and bifunctional silyl ether-based (BSE) monomers to induce a clever cleavage cascade upon exposure to free thiolate ion leading to nucleophilic aromatic substitution releasing a fluoride ion. The authors demonstrate this phenomenon through small molecule and linear homopolymer studies to illustrate the feasibility of the proposed mechanism. They then demonstrate degradation of PFP and BSE containing PEG brush terpolymers and pDCPD thermosets under organic and aqueous conditions with the proper positive and negative controls. This work outlines another tool through which to degrade ROMP based polymer systems and has potential to be useful across a broad range of polymer engineering and biomaterial applications. It is my suggestion that this manuscript be accepted to Chemical Science with the current score of 9 which can be increased to a 10 after addressing the few comments that are listed below.

Major comments:
1. Introduction: Please add citations to the thioester work which inspired the authors in sentence 1 on page 4. (Suggested examples: doi.org/10.1021/jacs.8b12154, doi.org/10.1039/D2SC06040J)
2. Small molecule model studies: A short justification as to why the authors picked 1-dodecanethiol as the model thiol for this study would add to first realization of this concept.
3. PEG-based graft terpolymer deconstruction under aqueous conditions: Out of curiosity, can the authors speak to the comparison of observed degradation rates in organic versus aqueous conditions? Both degradation timepoints were taken at 30 min, and the authors attribute enhanced aqueous degradation times over previous methods to the hydrophobic local environment of P1. The authors might consider including degradation rate studies in organic and aqueous conditions to strengthen the comparison and equivalence (or inequivalence) of the two base/thiol pairings.
4. Thiol-triggered cascade deconstruction of polydicyclopentadiene thermoset: The measured Tg of T1 is half that of T2 in Table S1, but the authors claim the thermomechanical properties are similar. Notably, when only 1 eq. of Nb-PFP was added to the thermoset, the Tg was better preserved. Can the authors add a comment as to why the 2 eq. Nb-PFP analogue was chosen over the 1 eq. Nb-PVP analogue for the thermoset degradation comparison study?
5. Thiol-triggered cascade deconstruction of polydicyclopentadiene thermoset: Figure 6A, T1 with THF + TBAF – at time 0 h, there already appears to be color in the solution and the final solution is much darker than without PFP in Figure 6B. Is this due to residual solubilized G2 or is the rate of degradation increased with TBAF treatment in PFP containing thermosets? Could the authors comment on the possibility of any synergistic degradation?

Minor comments:
1. Suggested Title Adjustment: “Thiolate-triggered deconstruction of bifunctional silyl ether terpolymers via a SNAr-initiated cascade” Since a thiol without base is shown within the paper not to trigger decomposition (Figure 4B), specifying “thiolate-triggered” highlights the necessity of the base+thiol for decomposition. If the authors agree, this distinction could be carried through the manuscript text.
2. General: Please ensure consistency between “terpolymer” and “copolymer” throughout the manuscript. Currently, “terpolymer” is in all of the section headings, but “copolymer” is used more frequently throughout the text and figure captions. Terpolymer is more accurate.
3. Figure 1B, “statistical copolymer” should be either be changed to “statistical terpolymer” or be kept being consistent with the rest of the manuscript depending upon decision to comment 2.
4. Small molecule 1H NMR shifts are reported in the methods section, but the corresponding chemical shifts for the polymer analogues are currently omitted from the SI. Please add labels to the polymer NMR spectra (Fig. S5, S11, S12, S19 or add chemical shifts to the polymer methods sections similar to the small molecules)
5. For completeness, please add the quantification of residual mass % in the Supporting Information for T2 corresponding to the images reported in Figure 6B.

Johnson and coworkers have satisfactorily addressed all my reviewer comments on the previous draft through their responses and revisions. In doing so, details have been clarified and the overall manuscript has been strengthened leading to the original report of a clever and elegant tool to degrade ROMP-based polymers. Please note that a small uploading error has impacted Figure 3B (currently a black box) and should be remedied before publication. It is my recommendation that this manuscript be accepted to Chemical Science.