My EG ds doesn't have a specific word finding difficulty, but he has an expressive language disorder (basically more global than trouble with finding specific words - ie, inability to express thoughts in words in certain circumstances). I don't know if this will help at all, but fwiw, our ds struggled with this tremendously in elementary school. In 5th grade he started private speech therapy with an SLP who was very invested in wanting to see him succeed, and he's been in speech therapy ever since (once per week, with us practicing at home and with a ton of scaffolding from me on writing assignments). DS is 14 now, and has been in SLP therapy since he was 10. This may sound discouraging, but we really didn't see any significant results until almost a full year had passed, and even then, progress was slow - it was mostly learning tips and tricks for how to get his brain jump-started and up through last fall he still found writing assignments extremely stressful and frustrating. Then things kicked in and progress finally really started cascading for him, and he's come a long way in the past year.
The things that I think helped our ds the most were:
1) Working with a good SLP.
2) Playing word-generation type games (fun board games) before he started a homework assignment. This wasn't directly helpful with the actual assignment, but helped (how I don't know!) somehow rev up his brain so that he had less difficulty getting words out.
3) Giving him remediation and regular assignments *at his intellectual level*. The first inclination most therapists and teachers have for a child who obviously has a challenge in an area is to give them lower-than-their-ability intellectual level work to do while remediating. The difference in progress my ds made when given an appropriate intellectual challenge was huge.
4) Repeat repeat repeat repeat... etc... When a gifted child can learn some concepts extremely quickly, it's hard for parents and teachers to realize that with some challenges a ton of repetition is needed, even for a highly gifted child.
5) Making sure that outside of his area of challenge, ds had intellectually stimulating work and that he had self-confidence building activities that he could accomplish and be proud of. It's easy when students are young to get heavily invested in remediating challenges, but it's equally important for the development of their self-esteem to give them opportunities to shine

Re test results - my ds' SLP eval, on the surface, looks a-ok. His combined score was high average or something like that. However, when you look at the subtest scores, his scores were all > 99th percentile except for one area - and that was only around the 61st percentile. That may seem like a good set of scores with no worries - but that 61st was enough to diagnose an expressive language disorder, and there was no question at that point in his life, if you met him, you'd agree, he had a significant issue with expressive language! There was also an important note from the evaluator in his report - the subtest that he scored the 61st percentile on wasn't timed, and the tester noted that it took him an extremely long time to come up with the answers, which she felt was significant.
Is the therapist your dc has seen an SLP? If so, is he/she recommending a therapy program? Have you noticed your dc struggling with word finding?
Best wishes,
polarbear