This is because PayPal does not offer the option to split the payment in 3 installments when at the time of placing the order no payment is made, which happens when you select the option "1. TRIAL 21 DAYS (free)", since, at this time you do not pay ...
Good question, but the truth is that I have not tested with dust in suspension. I have tried to process images with haze caused by humidity, but not with the haze caused by dust in suspension, because where I live it is a rare meteorological ...