No wonder to me I hardly notice the drop-off issue. I was ignorantly & blissfully using MXP close to a year before I noticed the sponge deteriorating visually and only then I know that it has reached its useful life. So, yeah, MXP drop in performance is not an issue for me at this point in time.
But then, I wonder if newer ESN formula like Donic's Bluestorm Z1 ( another ESN super trampolinish rubber ) would escape this drop-off issue. I am tempted to use it in lieu of MXP.
There is a lot to consider here, and in my opinion, not that much actually comes down to the rubber (for you personally).
It comes back to the discussions you've been having on the blade you use.
Do you want something that will give you the greatest chance at improving, yet perhaps not "talk" to you in quite the same way?
Or do you want something that makes you do a happy dance every time you pick it up, but also restricts your improvement due to the fact it's too fast?
It's no different when talking about the rubbers.
Right now, my recommendation to you based on your willingness to improve and your current level would be to use a very average speed rubber that is nice and tacky - It doesn't have to be CRAZY tacky, but a good amount of grip (more than you get with typical EUR/JAP Tensor rubbers).
Why?
Your blade is fast, we all know this.
You say you want to learn to loop with a lot of spin consistently.
To be able to do that (well), you need a fast arm speed as you accelerate through the ball - However, when you use your Hinoki blade with MX-P or any other fast, tensor like rubber, your margin of error is 0.0000001% (at a guess), at your current skill level.
Even at higher skill levels, that set up is very, very fast. Just as yourself why so many pros are now using D09C on their FH? If you did a bounce test between MX-P and D09C, the former would bounce to the moon whilst Dignics would be very subdued in comparison.
However.... what are the downsides?
Effort.
It takes much more effort to loop with a fast arm speed and an average speed rubber - MX-P or another similar rubber will allow you to play the "Hollywood" shots more often, and give you that warn fuzzy feeling that your Hinoki blade also gives you.
For clarity, I don't think either route is wrong. You will have people tell you that you *need* to use this or that because it's optimal for your progression, but at the end of the day, you have to use what makes you feel happy.
Some people are just driven on improving at the quickest rate they can, and they don't care about equipment at all.
Others (like me), will aim to use equipment that is *somewhere* close to what they need, but then choose things that just make them happy.
So, to try and break it down a little.....
If you main goal is to improve at any cost (whilst still keeping hold of that Hinoki blade of yours), I would ignore MX-P or Bluestorm, and get something a little harder and spinnier.
MX-S isn't a bad option, as is Dignics 09C, but you could also spend half as much (maybe the new Glazyer would be an option), as you currently would not be able to get the most out of the rubber anyway.
You would then have to accept that your big old flat power hits are a thing of the past, and focus on spinning everything with maximum effort.
But if your main goal is to enjoy the sport, and use equipment that makes you feel warm and fuzzy (whilst still improving through playing as much as you can, you can pretty much choose anything you want.
If MX-P makes you feel good, keep using it.
If you'll not be able to sleep until you've tried Bluestorm, grab a sheet and test it out.
If you didn't notice any difference over a year of using MX-P, I would be very surprised if you would get much benefit from changing to another fast rubber - You certainly won't get more longevity than a year (if you are playing twice a week all year round).
The only time I think you'll feel a difference is if you drop down in speed, and then you'll realize each shot needs a bit more effort from you, and then you'll start to feel it.
A very long answer to say "use what you want", I guess 😂