So here is a concept - I thought why to use something liquid instead of solid as a separation layer.
Well you know what inspired such an idea! Yes, the Peachy printer. So I used liquid, but not water. I found properties of glycerin while experimented with pigments. Ordered some set of local pigments designed for home soap making. And they was mixed on the glycerin base. And that pigment with glycerin in no means wanted to mix with the resin no matter how well i stirred it. So then I thought - why not to try it instead of PDMS? It is very cheap, say few dollars for 100-200 grams.
But then I thought - if B9C will act as usual it will be a mess. I need to overcome sliding in some way - it need to be still. First I thought of disassembling entire sliding mech and coupling sensor with motor arm separately so that while it will move, it will "close" the contacts of the sensor. But I found simpler solution :)
On photos you can see it. I just lifted VAT up on the pencils so that VAT sliding mechanism will freely open/close beneath the "lifted" VAT
All sensors will be engaged as usual. But the main trick here is to fool the home sensor, coz it is it who responsible for build table descending accurately on the VAT window. After few simple workarounds and test I found the simple solution
You can see it on the photos too. Just glued with tape some alu foil (it should not be translucent, but hard paper will do it too) on the red part of build table arm in the place where it "contacts" with sensor. It should stretch down on the same amount as you lifted your VAT + added height because of thickness of glycerin. It's hard to measure it all precisely from the start, but solution is simple - you should use "spoofer" of the higher length then needed. And after few "calibrations" you can just cut it with scissors to the desired length.