Not sure if this has been asked here before..but using fake antenna diodes in openlane does have an area tradeoff (since we are including fake antennas in every input cell)..which could become a de-limiting factor in high instance count designs. Will we be going forward with this approach or do we plan on something else? Pl. do correct if my observation is incorrect.

Yep, already discussed, check the thread above, you are basically right, for any more complex designs this is an issue. Also as I pointed out above I do not think the current "solution" is the proper way to solve this