The manuscript submitted by Marc Guerre and co-authors presents a very interesting and clever strategy using thioester-based CANs to temporarily block free thiols by trapping them in dithioacetal groups, which can subsequently be released upon activation with the TBD catalyst.
The strategy is convincingly demonstrated through systematic stress-relaxation experiments, showing that although the relaxation time increases when thiols are blocked, this effect can be compensated by increasing the catalyst concentration.
Overall, the manuscript is very well written, clearly structured, and experimentally well executed. Only a few minor issues or typographical errors are present, which can be easily corrected and which I detail below.

There is, however, one aspect that concerns me (and the reason why I recommended major revision): the manuscript aims to demonstrate that the C-BT systems significantly improve creep resistance. This is shown in Figure 5, where C-BT5% (hypothesized to be more creep-resistant) is compared with C-FT1%. However, from the figure it seems that the slope d(ε)/dt at 110 °C is much larger for C-BT than for C-FT, which contradicts the expected behavior. In addition, the residual strain values being compared (0.19% for C-BT vs. 1.14% for C-FT) cannot be directly compared because the imposed strain is different (≈0.1% for C-BT and ≈1.1% for C-FT) and so it is the maximum strain achieved. All this seems to weaken the main argument regarding improved creep resistance. It is also possible that I may be misinterpreting the data, as some colors in the figure—especially those at 110 °C—are difficult to distinguish. For this reason, to understand better the argumentation of creep reduction, I strongly recommend adding a table including:

• dε/dt (the slope during the creep stage),
• ε_max (maximum strain reached under constant stress),
• ε_residual (residual strain after stress removal and recovery time), and
• % recovery (recovered strain relative to ε_max).

This would allow a clear and quantitative assessment of whether the proposed improvement in creep performance is indeed significant. I would also suggest adjusting the color scheme to make the differences more evident. These improvements would be highly appreciated by the reader.

Additionally, as a suggestion, if the experimental setup allows, it would be very valuable to know the thermomechanical properties of the materials being compared (for instance, through a temperature sweep at constant frequency). Since the crosslink density changes, storage modulus and tan δ (and the corresponding Tg) should also change. Although the Tg values from DSC do not differ significantly, comparing the overall thermomechanical behaviour could be quite relevant.

As a further suggestion—again, only if the equipment allows it —a temperature sweep at constant frequency (or a multi-frequency test at constant temperature) could also help reveal the more pronounced counterintuitive dissociative character of the thiol–thioester exchange in C-FT compared to the less pronounced behavior in C-BT.

Other minor points:
• Page 4. The text states: “The molar ratio between the thioester and the tetra-thiol was adjusted to leave 100%, 77%, 53%, 30% and 5% …”, but elsewhere in the manuscript the value 50% is used. Please update this for consistency.
• Page 4. The text says: “All these materials were then subjected to stress relaxation experiments (Figure S2–S17 for non-normalized, normalized stress relaxation and corresponding Arrhenius dependency). …” but it should read Figure S12–S17.
• Page 4. The text states: “The fastest stress relaxation was observed for the material containing 100% free thiols, with relaxation times of 37 s at 150 °C.” However, Table S2 lists 99 s at 150 °C for C-FT-100%FT-1 wt%TBD. Perhaps another temperature was intended?
• As a simple and useful improvement, I recommend adding confidence bands (for the linear regression) to the Arrhenius plots. These would clearly show that, in many cases, the activation energies are similar or statistically indistinguishable as the authors say.