Thanks for the comments.
@Novelty
Two tiles may be not enough, but I was also trying to provide uses for tiles that we don't otherwise use . . . .
There are a lot of blocking opportunities in the game now, but I take your point that this could be interpreted as somehow "ultimate" in some cases - playtesting may show how serious this is.
I have looked at your row,row,row, . . variant and it has some ideas I like. I will try to playtest it and get back to you.
@Scott
Thanks for the references. WOW! They are way more ambitious than what I had in mind. They all involve creating new tiles and I have not yet seen a really easy way to make new tiles that are not touch sensitive when pulling from the bag. I have seen the stuff posted elsewhere on this forum about buying the correct card stock etc. but it seems just too much effort for me and then everyone else would have to be prepared to do it as well. I think that the best variants require minimal extra preparation effort. And anyway my object was to try to use up the tiles we already have