I have found the following.

Lesser starred horses (one and two stars) do good in halters until their career experience earings outrank that. It takes time. But by the time the horse is 18, with very few exceptions, these horses come in at level 50 or above. Acceptable to pass on the training boost to an offspring.

Three stars and up do best in halters until the horse's discipline level is at least first tier, regional level. Then it's a matter of seeing where the horse places to balance out the experience earned versus the halter experience earnings. Depends on the horse, the competition and the overall stats balance.

Yes, crossbreeds are at a disadvantage to pures, especially when it comes to halter show availability. But if the crossbreed is bred from a set of horses that has already been leveled up appropriately and in a certain discipline, then it's fair to start such a horse right into a discipline and have them succeed.

I don't know personally if the show, halter and career is evenly balanced. It comes across as mostly it is, to me and my overall experiences thus far. Perhaps it could be improved or maybe it's working now as our admins feel. But where a horse might fail in one area, there's another to allow it to succeed. Which if this was the driving factor, it does feel like it balances the maximum earnings much better.

And, of course, it's all in how each of us plays the game and what our goals are. My primary is to develop good and competitive discipline stock, but I must train them up to get to an acceptable minimal level first. Right now (the better stars earn more in halter than they do discipline), it's been upgraded to at least Tier 1, International level, before I'll be switching my stock from halter to discipline (with few exceptions). I am just about ready to break that boundry.

:) This has been my experience, but others may feel and experience things differently. Hope it helps!

I would love to see an achievement field on horse profile for 1st, 2nd and 3rd place in halter and discipline!

About the balance between disc and halter (career should stay as it is), I disagree. Imo, disc is medium risk medium reward while halter is high risk high reward. But halter shows also have a lower reward 'ceiling' than disc in the long run. Best experience you can get in halter is in 5-star tier and you get 2100 exp for 1st place. A horse scoring 1st place in International Tier 2 is 2055 exp and 2265 exp for Elite Tier 2. There is 5 tiers but no higher category than 5-star for halter. Halter shows have limited entries, you can't enter more than 10 horses/foals per category while disc don't have limitations (and 5-star halter shows sometimes don't run for days du to the lack of entries :/). You can enter 5 halter shows a day vs 10 discipline shows. Say you place 1st in 5 5-star halter, that's 10,500 exp.  10 1st-place at foundation tier 2 will give 10,050 exp and 10 1st-place in local tier 2 will give 12,150 exp. I personally think halter shows are great to boost a breeding program but discipline is the endgame. I would only change the 'range' of exp between first and last place in discipline. Currently, placing last in disc will get you not even 10% of the exp the first place will get and I do believe that's pretty harsh. Something like 20% would be better.

I agree that halter do put non-purebreeds (grades can't halter either) at a disavantage at times, especially for foals. Iirc, there is an idea floating around for halter shows run by clubs but I don't have more info on that.

You're also right that halter title point earnings are incredibly low but I don't feel strongly about it so no opinion.

Last point about earning PS in disc, I disagree too. We already have training boost that well... boost the PS we can train each week. I feel like adding PS reward would be overpowered (well, unless it's as low as title point earnings!).