I think that splints save bendy people from the downward spiral of pain, reduced use, weakened muscles, decreasing joint stabilisation, more pain, and a reinforced tendency to use the affected digits even less.

However there are medical professionals who do not believe in splints and, being medical professionals, their prejudices are impervious to evidence: doctors and physiotherapists consider themselves rational but, for the most part, their professional opinions are more of a taught belief system than an process of scientific logic.

Their actions against those who challenge the belief system can be quite shocking - as you well know from other aspects of your life.

Which is to say: you may need to find an excuse to seek advice from another physiotherapist.