Record yourself on good equipment and listen carefully. It sounds different out there. I have been through the safari many times and have a huge collection. Initial impressions are deceptive. I recently was happy with one set up. A friend offered me a trumpet to try and I recorded it but found some issues I had not expected. After an evening of trialling various options I reverted to a trumpet I was considering selling with a mouthpiece I had dismissed some time ago. Two months down the line it has settled well. Watch Wayne Bergeron talk about his Japan experience.
On your point re shallow pieces. I bottomed out quickly and had little stamina. Since doing this course I can now play a Shew 2( not my regular piece) as I feel much more efficient but still tend to over work. Once I completely back off things start to happen. I will never be or want to be a lead player but it is nice to know you have the range when required.I have gone from a nothing above the stave player to consistent high C and above in two years but still nowhere near fully efficient. Post Covid will reveal the true value when I start playing with other people again.