[Kovarex] Variables in parametrized blueprints not working if formula field not empty

[Tripeo]

Hello, I didnt search through the forums in case this bug exists or not sorry

The bug is next - when I create the parametrized blueprint - I can mark the field as variable, then I put some text, then I remove checkbox of variable. And when I place this blueprint it doesnt ask me to enter parameter anymore

So steps to reproduce:
1) create constant combinator
2) create 2 signals in it - iron * 100, copper * 200
3) press ctrl c to copy the combinator
4) press b to open blueprint storage and place new blueprint there
5) press right click on your new blueprint - it opens blueprint edit screen.
6) press parametrized blueprint - it opens parametrize window
7) mark checkbox in front of field "100" (our iron signal value)
also place variable name as "x"
also mark checkbox "formula"
also place text in formula "150"
8) Now remove checkbox "formula" (but dont remove the text "150")
9) Save blueprint
10) Try to place the new combinator object using your blueprint

Actual result - there is no any window which ask me to set the parameter value for iron
Expected result - there should be window asking me to set the parameter value as "parameter checkbox was marked"

Actual problem happens only when there is some text in "formula field" even if "formula checkbox isnt marked"

[Tripeo]

Also attaching screenshot of combinator config

combinator_bug.png (2.05 MiB) Viewed 220 times

combinator_bug

[Yodo]

Please post the Factorio version in which this happened.