Oversize Message Mailtip is pop-up dialog only?

I feel like I've searched this to death, but maybe I'm missing something.

Normal mail tips (large # of recipients, out of office, etc) appear as an "in line" at the top of a new email. Wonderful.

But when I set a maxsendsize on a mailbox, the mailtip for the user appears in a pop-up dialog. I just want to confirm this is by design?

I would like the ability to simply warn users when they are sending a large email with an "in-line" mailtip, as opposed to restricting it. Even better, I'd like to customize a mailtip with a link (ex sendthisfile.com link or something) when they attempt to (wishful thinking?). Without blocking it completely. The existing rules don't let you mix "maxmessagesize" with "policytip" though.

I can sort of do this at the transport level with a rule that returns an ndr to the user, but by then the user has already saved it in their sent items and wasted the time transporting to their mail server.

If anyone has any clarification, ideas, or direction for me.... I'm all ears.