I came to know in general Memphis city above 40% to 60% vacancy on average in apartment properties I hope it’s not true Any reason for such high vacancies?

In Austin, it is more of an appreciation market, and the high taxes make it hard to cash flow here.

However I have let tenants go for being too high maintenance. 

Every following generation will be leaps better.You are taking the thought process all the way to it's ultimate end, where robots provide all labor.

We have informed a tenant in writing that their lease will not be renewed when it ends on 10/31/24. 

The high volume guys are working on very slim margins.

It lacks a little in the property accounting side though, so if you end up growing your portfolio, it might be more useful to use software with additional features such as bank feed integration, advanced tax reporting, and receipt scanning. 

In other words, the evicted tenant's bad attitude (and actions) begin to poison the other tenant, and an eviction notice is the end result.

Does HELOC and other home equity financing methods work in the current high interest rate environment?

The 'what you get' for the money factor is highly applicable from Brookings to Astoria and licensable STR coastal vacation rentals are still regularly attainable at workable terms, Luxury and oceanfront and lakefront properties tend to perform above the 10% of valuation in gross annual income for prime coastal STR's and as an example I've seen a $2.1 Million Oceanfront home produce $300k in gross annual income.