Hi, sorry for the late response...
Let me see if I understood. You want, basically to set a temperature interval and keep the temp in that interval. Let's say you put an upper limit and a lower limit.
Low: 20 and High; 25
and if the current temperature is 18 then turn the heater on and the cooler off;
if the current temperature is above 25 like 28 then turn the cooler on and heater off;
if the current temperature is 23 then turn the heater and the cooler off;
I understood correctly?

I understood you want to have a single temperature and not an interval like I described.
and with hysteresis. I would go on intervals like I proposed first time but with hysteresis for not killing the cooler and the heater. And I would go like this because I see it more flexible and I think would work for you too if you are setting both low and high on the same value. I think;

The problem is that I do not have time know and I'm planning to refactor this project because I don't like my code that I wrote. In fact I never like my code after it passes some time :)...

So, if you fork it I cannot grantee that I will be able to merge it after. and to merge it before refactoring is possible to be hard to refactor...

But nevertheless is a great idea and I will implement it;
Meanwhile, maybe you can achieve what you need by using same not twice in a workflow one for lowering temperature and one for rising it... I think you would have some work to there and is not user friendly ....

aa no problem, be my guest :) yah maybe I can merge it ...

What part of the code would need to be changed in order for this to work for cooling. I want it to turn on when the temperature is higher then the target value rather than lower as it work now.

Did we add this an option for it to switch heating or cooling or add it as one module? I would like the same