Is this a reasonable plan for flight change?
 

So I am flying FRA-EWR-HOU-LAX on Saturday getting to LAX at 10:26 pm.

My FRA-EWR flight gets into EWR at 2:15 pm and EWR-HOU departs at 4:25. Since I'd prefer two flights rather than 3 and I don't need the extra flights for EQM, I am thinking I may do the following:

There are flights EWR-LAX at 3:25 pm and at 7:15 pm. Both have a lot of available seats and changing flights only costs $25 for Gold elite. I want to change to the 3:25 flight, but then I will only have 1:10 to go through customs. I am assuming that in case I don't make it, they will just put me on the 7:15 flight since that has plenty of seats. Or is that really too risky and I should just change to the 7:15 flight right away to guarantee a seat to avoid getting stuck in EWR? I guess worst case scenario, I'll end up on my EWR-HOU-LAX flight and just end up losing $25. What would others do in my situation? I would rather sit in EWR for 5 hours and get a massage/nails done at the spa than be on a plane those extra 5 hours.

Once you change, you're not guaranteed space on your original flights if you misconnect. Anything could change between now and then, and inventory can be eaten up after you make the change.

So worst case is not you get back on EWR-IAH-LAX, rather worst case is you get stuck overnight in EWR because everything else is full after you spend all afternoon unsuccessfully trying to standby for flights after having given up your original, confirmed booking.

Out of a hub like EWR, flights can fill up quickly. All it takes is a bit of a backup at EWR, and inbound connections get hosed, and then later evening flights start filling up quickly as people get protected and rebooked.

If you're not checking bags, I would try to standby/SDC after arriving in EWR to play it safe. Had the 1:10 been a bit longer I would've just SDC'ed it earlier, but 1:10 is too risky, IMO, to give up confirmed space afterwards. Also, you don't want to blow $25 for the late flight given that you really want the earlier one.

Right, so the issue is I have bags to check and that's why I have to make the change ahead of time. 1:10 definitely won't be enough time to actually go with my bags to the check in counter.

Maybe I will see the day before how full the flights are. I mean, I guess my main question is whether 1:10 is enough time and what are the chances it won't be... flights out of Germany don't seem to get delayed much and I am not the type to play it safe in case there is only a 25% chance of misconnecting... if there is a 75% chance on the other hand...

The FRA flight can be on time, but are there other flights due in at the same time? What about other flights that should have arrived before yours but got delayed

then cant tell you how many times we arrived on time or early but had to wait for a Gate or wait close to 1/2 for the bags to 1st start coming out. I usually use EWR when flying Intl, and if I wasnt based a few miles away but heading to LA like you are, I would Never think of doing what you are since theres just too many things that can and probably will mess it up at EWR!

My last trip the bags didnt start coming out for 35 mins, I was the 2nd person at the belt and when they did Priority werent the 1st ones either as they should have been. Took close to an hour for me to get both checked bags. true its usually not so bad but it does happen

1:10 is just way too little time with all that goes wrong, Im not saying its not possible to end up 1:10 as being enough time but I sure as heck wouldnt place even a $1 bet on it

Changing to the early EWR-LAX non-stop flight should be free if you're already at EWR. I wouldn't make the change prior to getting back airside in Terminal C because the risk of a misconnect is too high for my comfort level. If you miss that you can then see if the later flight is available and make the change then for the $25 SDC fee.

I can be Wrong (wont be the 1st time ;) ) but once the OP hands in their bags for whatever flight they just gave up being able to SBY or SDC. Everything has to be done before they recheck their bags

So if nothing is done before departing FRA (confirmed)then the OP will need to get their bags and find their way to the check-in counters upstairs. I dont know if I would trust the recheck counter downstairs to handle a SDC or SBY

You have to collect your bags in EWR anyway. Instead of handing them over, go to the counter that's down there.

I missed the follow-on post that mentioned bags. In that case the OP should deal with it at the bag-drop counter. Confirm the change there - either to the earlier flight if there is time or to the later non-stop. But they should do it in EWR, not in FRA, IMO.

I am not sure which is the check in counter down there. I only know the one where you leave the security area with your bags. Can you give more precise instructions of where exactly it is so I can find it. This seems like a good plan to wait until EWR to switch.