Thank you for the advice-- I've been using the same straw pellets as you have-- but I've never had the kind of issues you described. I think maybe it's because I always pre-hydrate them before mixing.
If you do that (and I stress that you have to go easy on the water) then it becomes the same consistency as fine vermiculite or sawdust-- crumbles up easy and does not really stick at all.
Where you get in trouble is using too much water-- the pellets will clump together a lot and if you smash them in that condition they'll stick into denser pieces- but you correctly observed yourself that once the moisture equalizes, the straw behaves like...well... straw, hehe, and will break up easily.
Even if you make a soupy pellet mix, you can counteract it with verm or coir, or stuff like cactus soil, and the mix will remain the right consistency for colonization, and the pellets will break apart as easily as sawdust does.
If I had more room I would probably get some baled straw for the aeration and "channeling" abilities it gives the mycelium, but my space is extremely limited and I don't have that room. These pellets are an excellent alternative, but they require extra care in preparation for sure.
With the basically powderized straw that these pellets break down into, you definitely do have to be thoughtful in how you use them-- because they will get gummy and gross if you overdo the water
I used this straw in my Semperviva mycobag-- worked great-- and the trays I made for my pans almost the same way (just without the clay mud and wood) have all colonized very well-- so this stuff works!