The devil is in details, usually. For example charting is heavily based on time on x axis, but all range bars don't work that way. Yet proper visualization is absolutely essential in the strategy development stage, where most time is spent. That's why I did this history trick, to cheat charting and be able to at least visualize properly.

Most of indicators should continue to work unchanged, but not all. But for indicators that depend on time heavily, counting bars in many ways represents time, but market time, not wall clock time. Yet, all that code would probably need to be carefully screened and adapted where necessary. For example, Slippage is very cleverly implemented right now in Zorro, because it's based on time, but it would then obviously need to be adapted to fit range bars. Finally, even though for example renko bricks are OHLC, essentially only 2 prices make sense, possibly even only 1 (close) so one needs to be very careful. Actually, I think standard renko bricks could be problematic for all the same reason why I discarded median renko as an option. Zorro trades on open price of the next bar, and I'm not sure that when renko reverts direction, that the open price is really tradable.

So, lots of details really, what I wrote above is probably just a tip of the iceberg.