Simple Buckboost current source controller IC required

Hi,
We are seeking a Buckboost SMPS controller IC which allows a 2A current source into a 18-30V load, from an 18-30V input.
(ie as attached)
Preferably with the high side drive on the chip.
Do you know if there is anything offtheshelf?

LT8705 does the job but is very expensive and way over-spec'd for the simple task...

Surely this is a gap in the market for the semico's?

LTspice sim and PDF schem attached)

There are a bunch of two-switch buck-boost controllers available. Have a look here: https://www.ti.com/power-management...s.html#p1129=Buck-Boost;SEPIC&sort=p1129;desc

If you use a dual inductor, you can use any boost converter IC in SEPIC or flyback configuration to achieve a similar result.

Have you looked at the LTC4020? This is a buck boost battery charger. Instead of buying a buck boost controller and trying to convert it to a constant current source, why not buy one that regulates the output current?