I always thought hAP lite (and other such devices) can only receive power through its microUSB port cause there's no schematics for USB-connection or even data line isn't just connected. So I thought there's no possibility to add new interface like a USB-modem. Now it seems I lived in a lie.

But modem (connected via 5VUSB power injector) doesn't work with (tested with hAP mini 6.44) neverless. Maybe there's no package or something...

it's not necessarily a lie.
you need a certain hw revision of your hap lites/map lites/whatevers with microUSB on them.

the best way to check this out is to upgrade them to 6.44.x+ and if you have an /interface pwr-line entry after the upgrade, you have a compatible one.

https://i.mt.lv/cdn/rb_files/PWR-line-190410141212.pdf

The PWR-Line is a replacement power adapter for your microUSB powered MikroTik router. It’s compatible with all the latest microUSB powered devices made by MikroTik, a simple software upgrade to v6.44+ enables this feature (supported by the mentioned devices with serial numbers that ends with /9xx. PWR-LINE functionality is also supported by some of previously manufactured units - if you have unit with serial number that ends with /8xx , upgrade to 6.44 and see if PWR-LINE interface shows up).

I have /interface pwr-line entry in my Map Lite, but the USB data certainly does not work.