CP - Don't be put off by Gavin's 'vagueness' of wanting to get too involved whilst you have another FS
I know with Lou when we both went to see him - he had so many ideas but kept repeating that it wasn't for him to step on other FS's toes, or muck around with their cycle protocols... but he would be more than happy to advise & consult if the FS was willing.
When I went to see him & he figured out my issues - he told me what he thought I should do but said the same thing about not stepping on my (at the time) FS's toes as well.... as soon as I explained to him that we would be changing clinics & cycling under him from now on, it was like he just went 'Well, let's bring it on then!'
For my upcoming cycle, he's been extremely thorough & gone over with me a number of times exactly what I'll be taking, exactly why, and exactly what each drug etc will do - and what he's hoping to achieve in each stage of the cycle from the beginning to the end of the 2ww... and hopefully further on into a pregnancy...
I'm with BW - I'd personally switch - but I'm bias & I love Gavin
It sounds like Dr L is open to discussion about looking into it further - wait until your next appointment & see what feel you get from there.... if you feel as though you don't think everything is covered, perhaps look into things further with Gavin from there.
Good Luck hun - and as much as its another thing to deal with on this horrid journey, its fantastic you have some answers... it can only bring you closer to your goal
Lots of love xxxxxxxxx
ETA - I can second everything BW has to say on the side effects of prednisone.... I've got a constant ring around my middle thats horrid

..... something easy to live with & even easier to forget about when you have your little one in your arms though, so it'll be all worth it hun xxx