Guidelines on Short-Leasehold Properties for REIT Evaluation

During the course, it was mentioned that properties with less than 30 years of remaining lease are generally not ideal. However, when I reviewed REITs like MIT and CLAR, I noticed that a number of their properties fall into this category. Given that these REITs each own over 100 to 200 properties, having some with shorter leases seems inevitable, especially since some industrial properties are originally developed with only 30-year leases. For example, CLAR has a total of 230 properties (including projects under development), of which 35 properties have less than 30 years remaining, representing approximately 15.2% of the portfolio. In such cases, what percentage of short-leasehold properties is considered acceptable? Or would any level of exposure to short leases be considered a strict no-go? Thank you.