THIS is how you make a twtm test chamber. Difficult puzzle, had to tinker for a couple of minutes to find a solution. Excellent puzzle.

@mood3rd: Well I guess that's more or less the intended solution in the last room... Actually I tried to make it to enforce a mechanism I found, but that was not enough, so I guess any solution should be okay ^^
Also I think I managed to inforce this mechanism in the second map I made ;)

ps. my 1st TWTM:
killer twin !
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=333760794

what I did in exit chamber: (delete when read)
in last chamber, I got recording to carry cube & sphere, from their buttons,
& drop just past the laser field.
then I stopped recording & put them back on buttons.
then I walked to other side of laser field & had recording bring me cubes.
then used recorded me picking up sphere & nudging cube to sphere's prior position.
then crossed bridge & pressed play.
recording brought me cube.
placed both on buttons. then recorded standing on weighted button.
pressed play & exited.

very good.
still crashing sometimes, while doing a quick save.
but prior save, still in tact, after re-start TWTM.
good TWTM concepts.
a green map :)
liked the sphere button teaser in 1st chamber.
(with it being usefull later.)
the easiest for me, was the hardest:
the way out of weighted button area, had me stumped longer than any other part of this map.
I was thinking portal 2.
then adjusted to thinking with time machine :)
2nd chamber also good.
good use of elements & twtm concepts again.
3rd chamber a good way to round off a good map :)
I also woundered about certain items & realised, you were taking care, not to trap the player :)