Finally I decided and pull the tiles job from existing contractor and pass to other tiles specilist.
Reason been
1) SInce my leaving room is replacing 2 x 2 tile, hence can't relay on top of existing 1 x 1 tiles either short or long term
2) Possiable of foot injury as the 2 x 2 edge designed was 90 degree type and no rounding egde protected, whereby 1x1 or 1x2 have a round edge. So if unbalance on the surface work it may injury our leg when walk.
3) Difficult to get balance if laying on top on the exisitng tiles with 2 x 2 (refer item 2), hence hacking away is a better solution
4) mixed of existing tiles area and new area
Also, the labour on this tiles specilist (I didn't told me the cost I been charge) is much more cheaper compared to existing contractor which charge me RM 5.50 sf for Wall / Floor, and skarting was RM 3.50 sf for in house / RM 3.80 for car pourche, if hacking involve will charge differently. Example hacked of existing 600sf area he want additional RM2K.
The tile specilist charging is RM4.50 sf for lay tiles and RM 6.50 for area that require hack existing tile out and replaced it and nd skirting is RM3sf. (Price included everything like material / rubbush ...exclude tiles)
I may be like a sucker

pulling the work out from the contractor, but some time just need to ensure we pay $$$ is a good reasoable way lol