I hit some barriers trying to update Do_Commands() in response to some changes, which forced me to stop and look to understand what it did.

Once I understood what it did I quickly looked at how to get rid of it. It's a bad version of DO which claims to be "faster" (though I very much doubt it is would be noticeably so). What it will do is break error reporting, debugging, etc.

R3-View has 2 uses in a switch statement in %host-draw.c:

case CMD_DRAW_PUSH

case CMD_DRAW_SHAPE

Looking at that REBCEC it seems like the only thing that's happening is that Do_Commands() gets called with the block...and it runs but with the commands getting the ctx->envr passed through.

I committed my guess on what would in practice provide the effective same behavior for these cases. It just has a global REBCEC pointer that is pushed when you start RL_Do_Commands and popped before it returns, and the Do_Command dispatcher passes on whatever the state is:

metaeducation@41ba66d

I would think it should be the same for reasonable input... because if it suddenly starts evaluating arguments that means that it was passing FUNCTION!s to the commands before--seemingly unlikely (?) It also could be a problem if you start calling other extensions and they're not able to interpret the context. But that also should not happen for existing code since the existing Do_Commands() calls were all are expecting to get the same context anyway.

If you run into problems with that let me know...