Don't worry about it, you've more or less kept an insane tempo up until now. Putting out new updates very quickly compared to what I've seen other asset developers do. So at least as far as I'm concerned, you're already waaaay ahead of schedule anyway.

By the way, is human models something you've experience doing and/or are planning on ever creating? Your environmental assets are superb, and in time I'll buy your other packs too. But as far as SGB goes, more realistically proportioned character models (that are different from the default "Type A") are somewhat scares, and I'm sure such assets could be very popular? 

If it's at all within your capabilities/skillset, maybe consider making character models to fit this pack for example? 

Besides that, how about some elevated road/train tracks for this set in a future update? ...maybe even a train to go with the tracks! :D