this is more of a discussion since it's not a certain issue and probably there are different ways of handling this. therefore the rather generic title.

... the more i look into this, the more complex it seems to become for me. one rather simple use case might be:

• user wants to make his pd_lua object's receive name configurable through a message

this can be easily done with a mechanism like (omitting all checks here):

function test:in_1_receive(x)
  self.recv:destruct()
  self.recv = pd.Receive:new():register(self, x[1], "receive")
end

it becomes more challenging though if there are dollar arguments involved. a typical option would be a message like receive \$0-foo to set the name to $0-foo, where $0 gets internally expanded to the actual canvas id. this is the mechanism that's common for Pd's gui objects like toggle, sliders etc.

if i send receive \$0-bla to the mechanism above, the dollar argument isn't expanded, which is probably expected, since $0 is obviously dynamic and shouldn't be forwarded in its expanded form, which would negate its purpose. but in that case, some kind of canvas_realizedollar()¹ function would be needed on the lua side, i assume?

when i use set_args() with the received symbol, it ends up in the patch file as \\\$0-foo - which means that the backslash gets escaped as well. might be expected, but prevents Pd from properly expanding the symbol on load.

attaching a pdlua object and patch for testing here² - the updated arguments of [test_dollar] are obviously only visible on reload or cut/paste.