A mirror frame this tall and this openly pierced has one real enemy, and it is not weight - it is racking. A tall rectangle wants to lean into a parallelogram, and every square of timber you cut away to make the scrollwork takes stiffness out of the frame that would have resisted it.
Our master Indian artisans handle that in two ways, both decided before a single scroll is cut. First, the pierced sides are not carved as a chain of separate flourishes; each side has a continuous stem of solid timber running from the base moulding all the way to the crest, and the scrolls are carved off that stem. Whatever the frame looks like from the front, there is an unbroken path of wood up each side.
Second, the mirror plate is captured in a rebate on all four sides and backed by a board fitted into the same rebate. That back-board is what actually holds the frame square - it is the shear panel of the whole assembly, doing quietly from behind what the pierced front cannot do.
Get those two right and the carver is free to cut the front as openly as the design asks.