Obviously this doesn't work. The middle of a project is no time to switch tools and still remain on schedule. But, a schedule is required for a successful project, and there definitely are decision points and drop-dead dates. Consider the real constraints of your project when selecting tools and components, and the major learning curves associated with using these new tools and parts. The safest approach is likely to be the same approach used in your last project.
New technology is great, but be prepared to take some lumps during the learning process.
Not all engineered electronic technology fades away within six months of the design start. Most firms have a number of ancient designs using 6502 and Z80 processors or something similar. Although these older designs lack some of the features or speed of newer devices, the technology in this design is often the starting point for the next model. Technology incorporated in a design often outlives the product, and the technology developed is often the lifeblood of the organization. If quality technology is desired by management, both time and money must be allocated to its development.