I agree the consumer models tend to be underpowered. My first Mikrotik was the RB951-2n, which maxed out at 15 dBm (32 mW) and dropped to 9 dBm (8 mW) at max speed (150 Mbps). The hAP ac lite you own is thankfully around ~6 dBm more powerful, but that's still a little weak for thick walls.
I've since upgraded to the hAP ac, which ranges from 29 dBm (800 mW) down to 25 dBm (320 mW). That extra ~15 dBm does make a huge difference penetrating walls. (The RB951*-2HnD models are similarly high-powered if you only care about 2.4 GHz.)
A couple tricks I've used to increase link reliability through walls are to disable short guard interval (to protect better against reflections), and to disable higher bitrates (to avoid excessive failed retries). Those have made my WDS link through 4 walls pretty stable.
I've since upgraded to the hAP ac, which ranges from 29 dBm (800 mW) down to 25 dBm (320 mW). That extra ~15 dBm does make a huge difference penetrating walls. (The RB951*-2HnD models are similarly high-powered if you only care about 2.4 GHz.)
A couple tricks I've used to increase link reliability through walls are to disable short guard interval (to protect better against reflections), and to disable higher bitrates (to avoid excessive failed retries). Those have made my WDS link through 4 walls pretty stable.