Are there any plans to make solver accessible from LibreOffic basic?

In Excel you can place multiple buttons in the spreadsheet and programmatically let each button access solver with a different configuration and solve for a different problem.

Did you try the dispatcher slots? There are
.uno:GoalSeek
.unoGoalSeekDialog
.uno:SolverDialog
(I very rarely use the Solver / GoalSeek, and cannot tell something from own experience here.)

There are open bugs/requests concerning the solver. See:
tdf#113360