What's unfair about getting punished later in the season having more impact hypothetical impact, exactly? If you decide to rail on people and get yourself chat restricted near the end of the season and lose out on your rewards...That's your own fault. You dug your grave, you can't call it unfair when you did it to yourself.
Even still, getting punished and stripped of Honor has just as much hypothetical impact at the beginning of the season as it does at the end. People who remain consistently negative will have a much, much harder time climbing back up in Honor than someone who genuinely reforms. The only major difference is that the people who get punished near the end maybe realized that they fucked up and are probably going to lose out on their end of season rewards.
It doesn't promote being toxic early in the season, it just hammers home the point that you shouldn't be toxic period, since you could lose Ranked reward eligibility if you're not careful.
the only option to fix this is to have honor restore much faster after light chat restrictions (if need be it can stay painfully slow for bans and suspensions)
That's assuming that players losing their end of season rewards due to their own lack of self-control is a problem. It also assumes that they're going to immediately shape up and reform when they get the chat restriction, and that there are no other factors inhibiting their path back to Honor Level 2.
The first is not a problem - as mentioned before, if you get yourself chat restricted by the end of the season, see that you're likely going to be ineligible for end of season rewards, and think "oh, fuck, I really should not have done that." - That's a you problem. That's a problem of you deciding to be a jerk despite the potential costs. (Note; I'm saying "you" in the figurative sense here.)
And the second...Climbing Honor isn't just a matter of grinding out games. To quote Riot Tantram;
The(sic) climb in honor you need to ... be honorable.
Honorable/sportsmanlike players climb the Honor ladder faster than people who are low-key toxic or general assholes. And remember how I mentioned "other inhibiting factors" earlier?
What isn't known to a lot of players, though it has been mentioned, is that honor gains are slowed for unsportsmanlike players even when it isn't to the level to warrant a penalty.
Being negative and getting validly reported slows Honor progress.
If people want to reclimb to Honor Level 2, they have to actually be Honorable. And IMO, asking for easy solutions to personal problems (faster Honor recovery for chat restrictions, for example...) is not honorable. That's the kind of thinking that frames the system as the problem instead of the player.
let's face it (even if many won't admit it) many reports and chat restrictions are wrongfully given and given with poor context.
This is not a fact. The vast majority of chat restrictions are accurate - and I'd say it'd be somewhere within a decimal of 98-99% accuracy. Between the IFS being fed constant data, having the occasional penalty pulled for manual review to check for false-positives, and generally being pretty fucking good at discerning poor behavior, I could only ever imagine a chat restriction being wrongfully applied once in a blue moon.
...have to struggle a harsher punishment for it being later in the season.
It is no harsher a punishment than one that was dealt for exactly the same reasons earlier in the season. It's only perceived as harsher because of the late realization that actions have consequences.
Besides, I've seen occasional posts where players remark at how obscenely fast the reclimb is from Honor 0-1 or from anywhere to Honor 2. I vaguely recall one post that mentioned that they reached Honor Level 2 from 0 in about a week.
So, rather than trying to reach for cheap, easy, and ill-thought solutions - rather than trying to point to the system as the problem - look for an actual solution. Look at yourself as the issue instead of the system. Make the effort to reform, and you'd probably be surprised how quickly you climb back up.