I'd like to apply for a new card sometime between September and December, while at the same time I'd also like to request a HP CLI on my Barclays Uber. From what I've read with Barclays, you really want to wait at least 9 months if not a year before taking that HP since they're very conservative and take their sweet time sizing you up and determining if you're creditworthy.
So my initial plan is to apply for the new card in November, and try to get that HP CLI done before the new account hits TU. But my concern is the SUB on the new card may not last until Nov, or it would've been downgraded by then. So the earlier I apply the better. The problem with an earlier-than-November app is Barclays will obviously see the new account on TU when I hit the luv button, and knowing Barclays, I'm not sure if they'd even approve me for a CLI.
My question is has anyone ever had any experience requesting a HP CLI with Barclays shortly after getting a new card with another bank (say 3 months), and what was the outcome? I understand this is highly specific question but any input is much appreciated. 
Great question actually. Not considering doing that (yet) because I'm eyeing a BoA card, and while they typically pull EX, it's not 100% guaranteed. Plus I plan on trying for another SP CLI on my existing Cash Rewards card around the same time, and that definitely pulls TU, and I'd rather keep the HP off for as long as possible for best possible results.