The state laws (do not quote me) appear to not let these companies increase rates (or its not easy) to pick up the losses.

That helps some...but your variable expenses also go up too - property insurance & taxes - so a lot of your rent increases go to offset rising variable expenses.I started at the age of 47 in 2018 and we bought properties fast and furious - 12 the first year, 10 the next, and 9 in 2021 and currently have 38 properties. 

I don't know if I'm getting much appreciation on a duplex unless the rents are significantly increased.

I’m currently going through the process of getting a HELOC and feel confident we’d be able to fund a purchase using that but using PML has ultimately been a goal of mine and would like to incorporate it into one of these purchases if possible. 

pid=2141Houston Real Estate Highlights for December and Full-Year 2024:-Following two consecutive years of declines, single-family home sales rebounded in 2024 with 85,163 single-family homes sold compared to 84,038 in 2023 an increase of 1.3 percent; -Total property sales for full-year 2024 were statistically flat at 101,864 units while the total dollar volume increased 3.1 percent to $41 billion;-December single-family home sales climbed 16.3 percent year-over-year with 7,162 units sold;-Total December property sales increased 13.6 percent to 8,478 units;-Total dollar volume for December rose 20.5 percent to $3.5 billion;-The single-family home median price edged up by 1.3 percent to $334,290 while the average price increased 5.0 percent to $425,150;-Single-family homes months of inventory expanded to a 4.0-months supply;-The townhome/condominium market experienced declining sales throughout 2024, and in December, volume declined 5.8 percent, with the average price up 2.5 percent to $268,152 and the median price statistically flat at $234,250;-Townhome/condominium inventory improved from a 3.5-months supply to 5.4 months.

Typically if demand increases and supply is maintained prices go up. 

After a couple years and a couple different programs I can confidently say skip them all except Vena Jones Cox's the Guru Manifesto. 

Pretty incredible how rapid the demand has increased in the past 12 months especially. 

Other most common factor: Family Size increases due to marriage or having a child. 

So spending 200k on an ADU will likely not increase your property value by 200k.