2003 front tire question

I have a 03 custom with a 21in front tire. 2 metzlers me880 in a row started to crack between the treads within 1000k. Metzler said this is normal. My Indy said he's seen this on metzlers. Has anyone else had this issue with metzler me 880 on their sportser???

If have the new metzler 888 on the rear with no issues. Can I put an Avon on the front and leave the Metz on the back?.

Thanks in advance!

T