No, melting point is largely irrelevant when using solvents.
This is a huge misunderstanding in this community as most of these guys have no education in chemistry.
Melting point refers to the point a compound melts in a dry heat, not in a liquid.
Melting point is the measure of how much energy it takes to make the phase change from a solid to a liquid, a solvent is used to reduce the amount of energy is takes to make that phase change. Because of this there is literally no need to get a solution up to the dry melting point of a compound as the solvent reduces the actual amount of energy needed to make the phase change happen.
Tl;dr: there is no need to get your brew to the melting point when using solvents like BB, just get it warm enough to ease the powder into solution. More heat=potential oxidation of your hormone powder and that is really not good.
Skilled brewers use the least amount of heat possible. Anyone who says you have to get it to the melting point in a solution with solvents does not have any understanding of chemistry.