Given the strength of the entry list for Bratislava, I think Alex is probably wishing now that he'd entered Eckental ! I don't think he expected the entry list to be anywhere near as strong, 16 top 100 players in a challenger is crazy ! They should upgrade it to a low level ATP.

I think that Alex does actually prefer indoor acrylic to carpet. All the challengers in GB are on indoor hard as was Mons and Bergamo. Belgrade is the only tournament where I can remember Alex doing well on carpet. I think the reason is that carpet tends to keep low, favouring the serve-volleyers while Alex is predominantly a baseliner.

If Alex can reach one quarter-final in either Bratislava or Ukraine, it'll be a massive confidence boost given how strong those fields are. On his day, he could beat a lot of players who are entered for those tournaments.