is the intercept B0 in y = B0 + B1X1 + .... fit differently for every feature x1.
Is it different for every feature coefficient or the same for all feature coefficients and why so?
is the intercept B0 in y = B0 + B1X1 + .... fit differently for every feature x1.
Is it different for every feature coefficient or the same for all feature coefficients and why so?
NO, there is only one intercept in the model, with only one value. It is not clear from where your misconception comes, but from the algebra $$ y_i=\beta_0 + \beta_1 x_{i1} + \beta_2 x_{i2} +\dotso +\epsilon_i $$ which is the multiple linear regression model, the constant term (intercept) $\beta_0$ has only one index $_0$, is only one symbol, and can only represent one number.
The different predictor variables $x$ have indices $_{i1}, _{i2}, \dotsc$ the last number $1,2,\dotsc$ indicating which predictor variable it is. This number does not occur with the intercept, so there is no connection.
@user20637 says in a comment The intercept will (often) change if a predictor is removed or added. This may be the source of the OPs misconception. If so, the following post will help you: Why is the intercept in multiple regression changing when including/excluding regressors?