That's looking good. I'm sure it will hold up fine!
It's got the classic design that is tried & tested.
There's a very good write up in the sticky section of this forum that elaborates on the size of 'rail' you should use for various spans. 2x4 for a 4' span, 2x6 for a 6' span etc.
I have never posted a link from my phone before, so here goes;
https://www.monsterfishkeepers.com/forums/threads/worried-that-your-stand-wont-hold-up.302232/
You may have already this. I find it very handy.
Great job so far!