Ok so your branches are better and more within limits. So we aim for a 3 UVI level at the branch. This is the UVB strength to simplify it. Veileds have a range of exposure of basically 2-6 UVI. 2 being the lowest and 6 being the highest level of exposure.
So fixtures and bulb strengths along with type of screen it is sitting on all impact these levels. Screen reduces the output by about 40%. Which is actually good for us with T5HO fixtures. Because they have an intense output level. So with your T5HO fixture and a 5.0 UVB bulb. Sitting on top of the aluminum window screen of your cage your looking for a measured distance of about 8-9 inches to put him into that 3 UVI level. Your sitting right about 7.5 inches now which is still within limits and exposure would be approximately a 4 UVI level. So still within the needed range. Now as baby matures and reaches adult sizes I would drop down the branches another inch. Right now he sits lower but the taller he sits off the branches he will be sitting in higher UVI levels.
Upper levels above 6 become dangerous for continuous exposure. With the sun the UVI level increases as the sun rises. High noon strongest exposure level then as it starts to go down it reduces again. So a cham is never in continuous high exposure levels in its natural environment. We do not know all of the negative impacts of over exposure. But the logical ones would include cancer, growths, skin issues. Etc. Just like us being out in the sun being burned. Those that do not use SPF to protect their skin and who are always out in the sun tend to have long term issues with their skin.
In Chams UVB is needed to help with the D3 conversion process that happens in their bodies. It is what keeps their bones strong and impacts appetite as well. So under exposure issues can be things like MBD.
Zoo med bulbs should be replaced every 9 months as well. So mark your calendar for that.
Him sitting on the branch like that is normal. They like to be comfortable basking and lay typically so that one whole side of the belly has complete exposure.