anthonypool89, I suggest your understanding of your pool water balance and situation is correct, and you should continue with your plan.
Adding calcium increaser (calcium chloride) is needed to avoid aggressive water conditions (that currently exists) and balance your water properly. That will especially help because of the upcoming cold-water conditions which increases water aggressiveness towards calcium. Adding calcium chloride will be very soluble as long as the water has a negative CSI (or LSI or SI, which do provide virtually identical numbers), and therefore, adding without filter grids installed won't cause problems.
Recommended Levels/Limits have been designed (based on the CSI) to provide some very simple guidelines for those who do not understand the CSI and how important it is for plaster-based finishes. Unfortunately, given that there are wide fluctuations in water temps and TDS which can't always be controlled, sometimes, even when the pH, TA, CH is within the recommended levels, pool water can still be overly scale forming or overly aggressive which leads to etching over time. That is the simple reality. And that is why Leebo correctly suggested that you raise the CH now and even adjust for even colder water temps coming up this winter. Two or three winters of aggressive water (lower than about -0.4 or -0.5) can result in significant etching which causes rough or pitted plaster. No one wants that to happen.
When water temps are within a narrow and reasonable range (and the TDS isn't high), then the recommended levels work very well. Since you seem to understand the CSI or LSI and how to adjust it, you are on the right tract.