That's a good idea. I should be able to read his 2nd serve. Usually I'm so focused on what I'm doing I don't watch my opponents serve motion well enough. He's a smart player that adapts pretty well.
what helps me vs strong 1st serves, is to stay on the baseline, or at times even step inside the court + block / chip them.
might sound counter-intuitive, but the more time I have, I will be trying to hit them, but vs a good 1st serve it's difficult to time, while I try to go full swing if I stay behind + this as well opens the angles to the server, and I am not Nadal, to return any ball coming on my side.
so, by forcing myself to stay close, I remove the option of hitting the ROS, thus I don't need to change the grip whether it goes to FH or BH, and chipping also removes the timing issue that comes from the swing.
standing close as well means that it doesn't matter whether it is a down the T, or wide, I will get there relatively easy
this also sometimes takes the server by surprise, which combined with (already) medium chip return, at least neutralizes the serve. if you can excel at chipping deep returns, it is even better.
if you stay pretty much at the same position for the second serve, you can then chip the second 1st service, or attack the weak 2nd service