I really like the new AutoInvests - but I could like them more.
There’s a few stocks I’m building up but by buying them below a certain price.
It would be great if I could set a recurring frequency/amount with a buy limit for better controlled DCA portfolio building.
E.g. buy £25 of company x each week when the price is below £10
That’s an interesting suggestion. I’ve passed it on to the team for consideration. 
A price limit and a valuation condition are doing different jobs — the limit only tells you what the last trade was, while a valuation test asks whether the business is still worth the price. One thing I would add alongside the limit is a cap on how much of the position can accumulate in a single month, otherwise a long drawdown quietly turns a planned allocation into a much bigger bet than intended.
That’s a fair observation and could be a useful feature too.
For now, I’d just delete the AutoInvest when it gets to the size I want. If it’s only buying once a week, I’m sure I’d be aware when it’s approaching my target.
Also the price limit doesn’t (so far as I’m aware) doesn’t tell me what the last trade was - it tells the app the maximum price I’m willing to pay (I.e the price limit) doesn’t it?